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# Time

class astropy.time.Time(val, val2=None, format=None, scale=None, precision=None, in_subfmt=None, out_subfmt=None, location=None, copy=False)

  Bases: `TimeBase`

  Represent and manipulate times and dates for astronomy.

  A `Time` object is initialized with one or more times in the `val` argument. The input times in `val` must conform to the specified `format` and must correspond to the specified time `scale`. The optional `val2` time input should be supplied only for numeric input formats (e.g. JD) where very high precision (better than 64-bit precision) is required.

  The allowed values for `format` can be listed with:

      >>> list(Time.FORMATS)
      ['jd', 'mjd', 'decimalyear', 'unix', 'unix_tai', 'cxcsec', 'gps', 'plot_date',
       'stardate', 'datetime', 'ymdhms', 'iso', 'isot', 'yday', 'datetime64',
       'fits', 'byear', 'jyear', 'byear_str', 'jyear_str']

  See also: http://docs.astropy.org/en/stable/time/

  Parameters:
    val python:sequence, `ndarray`, number, `python:str`, `bytes`, or `Time` `object`

      Value(s) to initialize the time or times. Bytes are decoded as ascii.

    val2 python:sequence, `ndarray`, or number; optional

      Value(s) to initialize the time or times. Only used for numerical input, to help preserve precision.

    format `python:str`, optional

      Format of input value(s), specifying how to interpret them (e.g., ISO, JD, or Unix time). By default, the same format will be used for output representation.

    scale `python:str`, optional

      Time scale of input value(s), must be one of the following: (‘tai’, ‘tcb’, ‘tcg’, ‘tdb’, ‘tt’, ‘ut1’, ‘utc’)

    precision `python:int`, optional

      Digits of precision in string representation of time

    in_subfmt `python:str`, optional

      Unix glob to select subformats for parsing input times

    out_subfmt `python:str`, optional

      Unix glob to select subformat for outputting times

    location `EarthLocation` or `python:tuple`, optional

      If given as an tuple, it should be able to initialize an an EarthLocation instance, i.e., either contain 3 items with units of length for geocentric coordinates, or contain a longitude, latitude, and an optional height for geodetic coordinates. Can be a single location, or one for each input time. If not given, assumed to be the center of the Earth for time scale transformations to and from the solar-system barycenter.

    copy bool, optional

      Make a copy of the input values

  Attributes Summary

  `FORMATS` | Dict of time formats
  `SCALES` | List of time scales
  `T` | Return an instance with the data transposed.
  `cache` | Return the cache associated with this instance.
  `delta_tdb_tt` | TDB - TT time scale offset
  `delta_ut1_utc` | UT1 - UTC time scale offset
  `format` | Get or set time format.
  `in_subfmt` | Unix wildcard pattern to select subformats for parsing string input times.
  `info` | Container for meta information like name, description, format.
  `isscalar` |
  `jd1` | First of the two doubles that internally store time value(s) in JD.
  `jd2` | Second of the two doubles that internally store time value(s) in JD.
  `location` |
  `mask` | The mask.
  `masked` | Whether or not the instance uses masked values.
  `ndim` | The number of dimensions of the instance and underlying arrays.
  `out_subfmt` | Unix wildcard pattern to select subformats for outputting times.
  `precision` | Decimal precision when outputting seconds as floating point (int value between 0 and 9 inclusive).
  `scale` | Time scale.
  `shape` | The shape of the time instances.
  `size` | The size of the object, as calculated from its shape.
  `unmasked` | Get an instance without the mask.
  `value` | Time value(s) in current format.
  `writeable` |

  Methods Summary

  `argmax`([axis, out]) | Return indices of the maximum values along the given axis.
  `argmin`([axis, out]) | Return indices of the minimum values along the given axis.
  `argsort`([axis, kind]) | Returns the indices that would sort the time array.
  `copy`([format]) | Return a fully independent copy the Time object, optionally changing the format.
  `diagonal`(*args, **kwargs) | Return an instance with the specified diagonals.
  `earth_rotation_angle`([longitude]) | Calculate local Earth rotation angle.
  `filled`(fill_value) | Get a copy of the underlying data, with masked values filled in.
  `flatten`(*args, **kwargs) | Return a copy with the array collapsed into one dimension.
  `get_delta_ut1_utc`([iers_table, return_status]) | Find UT1 - UTC differences by interpolating in IERS Table.
  `insert`(obj, values[, axis]) | Insert values before the given indices in the column and return a new `Time` or `TimeDelta` object.
  `isclose`(other[, atol]) | Returns a boolean or boolean array where two Time objects are element-wise equal within a time tolerance.
  `light_travel_time`(skycoord[, kind, ...]) | Light travel time correction to the barycentre or heliocentre.
  `max`([axis, out, keepdims]) | Maximum along a given axis.
  `mean`([axis, dtype, out, keepdims, where]) | Mean along a given axis.
  `min`([axis, out, keepdims]) | Minimum along a given axis.
  `now`() | Creates a new object corresponding to the instant in time this method is called.
  `ptp`([axis, out, keepdims]) |
  `ravel`(*args, **kwargs) | Return an instance with the array collapsed into one dimension.
  `replicate`([format, copy, cls]) | Return a replica of the Time object, optionally changing the format.
  `reshape`(*args, **kwargs) | Returns an instance containing the same data with a new shape.
  `sidereal_time`(kind[, longitude, model]) | Calculate sidereal time.
  `sort`([axis]) | Return a copy sorted along the specified axis.
  `squeeze`(*args, **kwargs) | Return an instance with single-dimensional shape entries removed.
  `strftime`(format_spec) | Convert Time to a string or a numpy.array of strings according to a format specification.
  `strptime`(time_string, format_string, **kwargs) | Parse a string to a Time according to a format specification.
  `swapaxes`(*args, **kwargs) | Return an instance with the given axes interchanged.
  `take`(indices[, axis, out, mode]) | Return a new instance formed from the elements at the given indices.
  `to_datetime`([timezone, leap_second_strict]) | Convert to (potentially timezone-aware) `datetime` object.
  `to_string`() | Output a string representation of the Time or TimeDelta object.
  `to_value`(format[, subfmt]) | Get time values expressed in specified output format.
  `transpose`(*args, **kwargs) | Return an instance with the data transposed.

  Attributes Documentation

  FORMATS = {'byear': <class 'astropy.time.formats.TimeBesselianEpoch'>, 'byear_str': <class 'astropy.time.formats.TimeBesselianEpochString'>, 'cxcsec': <class 'astropy.time.formats.TimeCxcSec'>, 'datetime': <class 'astropy.time.formats.TimeDatetime'>, 'datetime64': <class 'astropy.time.formats.TimeDatetime64'>, 'decimalyear': <class 'astropy.time.formats.TimeDecimalYear'>, 'fits': <class 'astropy.time.formats.TimeFITS'>, 'gps': <class 'astropy.time.formats.TimeGPS'>, 'iso': <class 'astropy.time.formats.TimeISO'>, 'isot': <class 'astropy.time.formats.TimeISOT'>, 'jd': <class 'astropy.time.formats.TimeJD'>, 'jyear': <class 'astropy.time.formats.TimeJulianEpoch'>, 'jyear_str': <class 'astropy.time.formats.TimeJulianEpochString'>, 'mjd': <class 'astropy.time.formats.TimeMJD'>, 'plot_date': <class 'astropy.time.formats.TimePlotDate'>, 'stardate': <class 'astropy.time.formats.TimeStardate'>, 'unix': <class 'astropy.time.formats.TimeUnix'>, 'unix_tai': <class 'astropy.time.formats.TimeUnixTai'>, 'yday': <class 'astropy.time.formats.TimeYearDayTime'>, 'ymdhms': <class 'astropy.time.formats.TimeYMDHMS'>}

    Dict of time formats

  SCALES = ('tai', 'tcb', 'tcg', 'tdb', 'tt', 'ut1', 'utc', 'local')

    List of time scales

  T

    Return an instance with the data transposed.

    Parameters are as for `T`. All internal data are views of the data of the original.

  cache

    Return the cache associated with this instance.

  delta_tdb_tt

    TDB - TT time scale offset

  delta_ut1_utc

    UT1 - UTC time scale offset

  format

    Get or set time format.

    The format defines the way times are represented when accessed via the `.value` attribute. By default it is the same as the format used for initializing the `Time` instance, but it can be set to any other value that could be used for initialization. These can be listed with:

        >>> list(Time.FORMATS)
        ['jd', 'mjd', 'decimalyear', 'unix', 'unix_tai', 'cxcsec', 'gps', 'plot_date',
         'stardate', 'datetime', 'ymdhms', 'iso', 'isot', 'yday', 'datetime64',
         'fits', 'byear', 'jyear', 'byear_str', 'jyear_str']

  in_subfmt

    Unix wildcard pattern to select subformats for parsing string input times.

  info

    Container for meta information like name, description, format. This is required when the object is used as a mixin column within a table, but can be used as a general way to store meta information.

  isscalar
  jd1

    First of the two doubles that internally store time value(s) in JD.

  jd2

    Second of the two doubles that internally store time value(s) in JD.

  location
  mask
  masked
  ndim

    The number of dimensions of the instance and underlying arrays.

  out_subfmt

    Unix wildcard pattern to select subformats for outputting times.

  precision

    Decimal precision when outputting seconds as floating point (int value between 0 and 9 inclusive).

  scale

    Time scale.

  shape

    The shape of the time instances.

    Like `shape`, can be set to a new shape by assigning a tuple. Note that if different instances share some but not all underlying data, setting the shape of one instance can make the other instance unusable. Hence, it is strongly recommended to get new, reshaped instances with the `reshape` method.

    Raises:
      `ValueError`

        If the new shape has the wrong total number of elements.

      `AttributeError`

        If the shape of the `jd1`, `jd2`, `location`, `delta_ut1_utc`, or `delta_tdb_tt` attributes cannot be changed without the arrays being copied. For these cases, use the `Time.reshape` method (which copies any arrays that cannot be reshaped in-place).

  size

    The size of the object, as calculated from its shape.

  unmasked

    Get an instance without the mask.

    Note that while one gets a new instance, the underlying data will be shared.

    See also

    `filled`

      get a copy of the underlying data, with masked values filled in.

  value

    Time value(s) in current format.

  writeable

  Methods Documentation

  argmax(axis=None, out=None)

    Return indices of the maximum values along the given axis.

    This is similar to `argmax()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used. See `argmax()` for detailed documentation.

  argmin(axis=None, out=None)

    Return indices of the minimum values along the given axis.

    This is similar to `argmin()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used. See `argmin()` for detailed documentation.

  argsort(axis=-1, kind='stable')

    Returns the indices that would sort the time array.

    This is similar to `argsort()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used, and that corresponding attributes are copied. Internally, it uses `lexsort()`, and hence no sort method can be chosen.

    Parameters:
      axis `python:int`, optional

        Axis along which to sort. Default is -1, which means sort along the last axis.

      kind‘stable’, optional

        Sorting is done with `lexsort()` so this argument is ignored, but kept for compatibility with `argsort()`. The sorting is stable, meaning that the order of equal elements is preserved.

    Returns:
      indices `ndarray`

        An array of indices that sort the time array.

  copy(format=None)

    Return a fully independent copy the Time object, optionally changing the format.

    If `format` is supplied then the time format of the returned Time object will be set accordingly, otherwise it will be unchanged from the original.

    In this method a full copy of the internal time arrays will be made. The internal time arrays are normally not changeable by the user so in most cases the `replicate()` method should be used.

    Parameters:
      format `python:str`, optional

        Time format of the copy.

    Returns:
      tm `Time` `object`

        Copy of this object

  diagonal(*args, **kwargs)

    Return an instance with the specified diagonals.

    Parameters are as for `diagonal()`. All internal data are views of the data of the original.

  earth_rotation_angle(longitude=None)

    Calculate local Earth rotation angle.

    Parameters:
      longitude `Quantity`, `EarthLocation`, `python:str`, or None; optional

        The longitude on the Earth at which to compute the Earth rotation angle (taken from a location as needed). If `None` (default), taken from the `location` attribute of the Time instance. If the special string ‘tio’, the result will be relative to the Terrestrial Intermediate Origin (TIO) (i.e., the output of `era00`).

    Returns:
      `Longitude`

        Local Earth rotation angle with units of hourangle.

    See also

    `astropy.time.Time.sidereal_time`

    Notes

    The difference between apparent sidereal time and Earth rotation angle is the equation of the origins, which is the angle between the Celestial Intermediate Origin (CIO) and the equinox. Applying apparent sidereal time to the hour angle yields the true apparent Right Ascension with respect to the equinox, while applying the Earth rotation angle yields the intermediate (CIRS) Right Ascension with respect to the CIO.

    The result includes the TIO locator (s’), which positions the Terrestrial Intermediate Origin on the equator of the Celestial Intermediate Pole (CIP) and is rigorously corrected for polar motion. (except when `longitude='tio'`).

    References

    IAU 2006 NFA Glossary (currently located at: https://syrte.obspm.fr/iauWGnfa/NFA_Glossary.html)

  filled(fill_value)

    Get a copy of the underlying data, with masked values filled in.

    Parameters:
      fill_value `object`

        Value to replace masked values with.

    Returns:
      filled instance

        Copy of `self` with masked items replaced by `fill_value`.

    See also

    `unmasked`

      get an instance without the mask.

  flatten(*args, **kwargs)

    Return a copy with the array collapsed into one dimension.

    Parameters are as for `flatten()`.

  get_delta_ut1_utc(iers_table=None, return_status=False)

    Find UT1 - UTC differences by interpolating in IERS Table.

    Parameters:
      iers_table `IERS`, optional

        Table containing UT1-UTC differences from IERS Bulletins A and/or B. Default: `earth_orientation_table` (which in turn defaults to the combined version provided by `IERS_Auto`).

      return_status bool

        Whether to return status values. If `False` (default), iers raises `IndexError` if any time is out of the range covered by the IERS table.

    Returns:
      ut1_utc `python:float` or `python:float` `array`

        UT1-UTC, interpolated in IERS Table

      status `python:int` or `python:int` `array`

        Status values (if `return_status=`True``):: `astropy.utils.iers.FROM_IERS_B` `astropy.utils.iers.FROM_IERS_A` `astropy.utils.iers.FROM_IERS_A_PREDICTION` `astropy.utils.iers.TIME_BEFORE_IERS_RANGE` `astropy.utils.iers.TIME_BEYOND_IERS_RANGE`

    Notes

    In normal usage, UT1-UTC differences are calculated automatically on the first instance ut1 is needed.

    Examples

    To check in code whether any times are before the IERS table range:

        >>> from astropy.utils.iers import TIME_BEFORE_IERS_RANGE
        >>> t = Time(['1961-01-01', '2000-01-01'], scale='utc')
        >>> delta, status = t.get_delta_ut1_utc(return_status=True)
        >>> status == TIME_BEFORE_IERS_RANGE
        array([ True, False]...)

  insert(obj, values, axis=0)

    Insert values before the given indices in the column and return a new `Time` or `TimeDelta` object.

    The values to be inserted must conform to the rules for in-place setting of `Time` objects (see `Get and set values` in the `Time` documentation).

    The API signature matches the `np.insert` API, but is more limited. The specification of insert index `obj` must be a single integer, and the `axis` must be `0` for simple row insertion before the index.

    Parameters:
      obj `python:int`

        Integer index before which `values` is inserted.

      values numpy:array_like

        Value(s) to insert. If the type of `values` is different from that of quantity, `values` is converted to the matching type.

      axis `python:int`, optional

        Axis along which to insert `values`. Default is 0, which is the only allowed value and will insert a row.

    Returns:
      out `Time` subclass

        New time object with inserted value(s)

  isclose(other, atol=None)

    Returns a boolean or boolean array where two Time objects are element-wise equal within a time tolerance.

    This evaluates the expression below:

        abs(self - other) <= atol

    Parameters:
      other `Time`

        Time object for comparison.

      atol `Quantity` or `TimeDelta`

        Absolute tolerance for equality with units of time (e.g. `u.s` or `u.day`). Default is two bits in the 128-bit JD time representation, equivalent to about 40 picosecs.

  light_travel_time(skycoord, kind='barycentric', location=None, ephemeris=None)

    Light travel time correction to the barycentre or heliocentre.

    The frame transformations used to calculate the location of the solar system barycentre and the heliocentre rely on the erfa routine epv00, which is consistent with the JPL DE405 ephemeris to an accuracy of 11.2 km, corresponding to a light travel time of 4 microseconds.

    The routine assumes the source(s) are at large distance, i.e., neglects finite-distance effects.

    Parameters:
      skycoord `SkyCoord`

        The sky location to calculate the correction for.

      kind `python:str`, optional

        `'barycentric'` (default) or `'heliocentric'`

      location `EarthLocation`, optional

        The location of the observatory to calculate the correction for. If no location is given, the `location` attribute of the Time object is used

      ephemeris `python:str`, optional

        Solar system ephemeris to use (e.g., ‘builtin’, ‘jpl’). By default, use the one set with `astropy.coordinates.solar_system_ephemeris.set`. For more information, see `solar_system_ephemeris`.

    Returns:
      time_offset `TimeDelta`

        The time offset between the barycentre or Heliocentre and Earth, in TDB seconds. Should be added to the original time to get the time in the Solar system barycentre or the Heliocentre. Also, the time conversion to BJD will then include the relativistic correction as well.

  max(axis=None, out=None, keepdims=False)

    Maximum along a given axis.

    This is similar to `max()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used, and that corresponding attributes are copied.

    Note that the `out` argument is present only for compatibility with `np.max`; since `Time` instances are immutable, it is not possible to have an actual `out` to store the result in.

  mean(axis=None, dtype=None, out=None, keepdims=False, *, where=True)

    Mean along a given axis.

    This is similar to `mean()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used, and that corresponding attributes are copied.

    Note that the `out` argument is present only for compatibility with `np.mean`; since `Time` instances are immutable, it is not possible to have an actual `out` to store the result in.

    Similarly, the `dtype` argument is also present for compatibility only; it has no meaning for `Time`.

    Parameters:
      axis `python:None` or `python:int` or `python:tuple` of `python:int`, optional

        Axis or axes along which the means are computed. The default is to compute the mean of the flattened array.

      dtype `python:None`

        Only present for compatibility with `mean()`, must be `None`.

      out `python:None`

        Only present for compatibility with `mean()`, must be `None`.

      keepdims bool, optional

        If this is set to True, the axes which are reduced are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the input array.

      where numpy:array_like of bool, optional

        Elements to include in the mean. See `reduce` for details.

    Returns:
      m `Time`

        A new Time instance containing the mean values

  min(axis=None, out=None, keepdims=False)

    Minimum along a given axis.

    This is similar to `min()`, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used, and that corresponding attributes are copied.

    Note that the `out` argument is present only for compatibility with `np.min`; since `Time` instances are immutable, it is not possible to have an actual `out` to store the result in.

  classmethod now()

    Creates a new object corresponding to the instant in time this method is called.

    Note

    “Now” is determined using the `now` function, so its accuracy and precision is determined by that function. Generally that means it is set by the accuracy of your system clock. The timezone is set to UTC.

    Returns:
      nowtime `Time`

        A new `Time` object (or a subclass of `Time` if this is called from such a subclass) at the current time.

  ptp(axis=None, out=None, keepdims=False)

    Deprecated since version 7.0: The ptp function is deprecated and may be removed in a future version. Use np.ptp instead.

    Peak to peak (maximum - minimum) along a given axis.

    This method is similar to the `numpy.ptp()` function, but adapted to ensure that the full precision given by the two doubles `jd1` and `jd2` is used.

    Note that the `out` argument is present only for compatibility with `ptp`; since `Time` instances are immutable, it is not possible to have an actual `out` to store the result in.

  ravel(*args, **kwargs)

    Return an instance with the array collapsed into one dimension.

    Parameters are as for `ravel()`. Note that it is not always possible to unravel an array without copying the data. If you want an error to be raise if the data is copied, you should should assign shape `(-1,)` to the shape attribute.

  replicate(format=None, copy=False, cls=None)

    Return a replica of the Time object, optionally changing the format.

    If `format` is supplied then the time format of the returned Time object will be set accordingly, otherwise it will be unchanged from the original.

    If `copy` is set to `True` then a full copy of the internal time arrays will be made. By default the replica will use a reference to the original arrays when possible to save memory. The internal time arrays are normally not changeable by the user so in most cases it should not be necessary to set `copy` to `True`.

    The convenience method copy() is available in which `copy` is `True` by default.

    Parameters:
      format `python:str`, optional

        Time format of the replica.

      copy bool, optional

        Return a true copy instead of using references where possible.

    Returns:
      tm `Time` `object`

        Replica of this object

  reshape(*args, **kwargs)

    Returns an instance containing the same data with a new shape.

    Parameters are as for `reshape()`. Note that it is not always possible to change the shape of an array without copying the data (see `reshape()` documentation). If you want an error to be raise if the data is copied, you should assign the new shape to the shape attribute (note: this may not be implemented for all classes using `NDArrayShapeMethods`).

  sidereal_time(kind, longitude=None, model=None)

    Calculate sidereal time.

    Parameters:
      kind `python:str`

        `'mean'` or `'apparent'`, i.e., accounting for precession only, or also for nutation.

      longitude `Quantity`, `EarthLocation`, `python:str`, or None; optional

        The longitude on the Earth at which to compute the Earth rotation angle (taken from a location as needed). If `None` (default), taken from the `location` attribute of the Time instance. If the special string ‘greenwich’ or ‘tio’, the result will be relative to longitude 0 for models before 2000, and relative to the Terrestrial Intermediate Origin (TIO) for later ones (i.e., the output of the relevant ERFA function that calculates greenwich sidereal time).

      model `python:str` or None; optional

        Precession (and nutation) model to use. The available ones are: - apparent: [‘IAU1994’, ‘IAU2000A’, ‘IAU2000B’, ‘IAU2006A’] - mean: [‘IAU1982’, ‘IAU2000’, ‘IAU2006’] If `None` (default), the last (most recent) one from the appropriate list above is used.

    Returns:
      `Longitude`

        Local sidereal time, with units of hourangle.

    See also

    `astropy.time.Time.earth_rotation_angle`

    Notes

    The difference between apparent sidereal time and Earth rotation angle is the equation of the origins, which is the angle between the Celestial Intermediate Origin (CIO) and the equinox. Applying apparent sidereal time to the hour angle yields the true apparent Right Ascension with respect to the equinox, while applying the Earth rotation angle yields the intermediate (CIRS) Right Ascension with respect to the CIO.

    For the IAU precession models from 2000 onwards, the result includes the TIO locator (s’), which positions the Terrestrial Intermediate Origin on the equator of the Celestial Intermediate Pole (CIP) and is rigorously corrected for polar motion (except when `longitude='tio'` or `'greenwich'`).

    References

    IAU 2006 NFA Glossary (currently located at: https://syrte.obspm.fr/iauWGnfa/NFA_Glossary.html)

  sort(axis=-1)

    Return a copy sorted along the specified axis.

    This is similar to `sort()`, but internally uses indexing with `lexsort()` to ensure that the full precision given by the two doubles `jd1` and `jd2` is kept, and that corresponding attributes are properly sorted and copied as well.

    Parameters:
      axis `python:int` or `python:None`

        Axis to be sorted. If `None`, the flattened array is sorted. By default, sort over the last axis.

  squeeze(*args, **kwargs)

    Return an instance with single-dimensional shape entries removed.

    Parameters are as for `squeeze()`. All internal data are views of the data of the original.

  strftime(format_spec)

    Convert Time to a string or a numpy.array of strings according to a format specification. See `time.strftime` documentation for format specification.

    Parameters:
      format_spec `python:str`

        Format definition of return string.

    Returns:
      formatted `python:str` or `numpy.array`

        String or numpy.array of strings formatted according to the given format string.

  classmethod strptime(time_string, format_string, **kwargs)

    Parse a string to a Time according to a format specification. See `time.strptime` documentation for format specification.

        >>> Time.strptime('2012-Jun-30 23:59:60', '%Y-%b-%d %H:%M:%S')
        <Time object: scale='utc' format='isot' value=2012-06-30T23:59:60.000>

    Parameters:
      time_string `python:str`, python:sequence, or `ndarray`

        Objects containing time data of type string

      format_string `python:str`

        String specifying format of time_string.

      kwargs `python:dict`

        Any keyword arguments for `Time`. If the `format` keyword argument is present, this will be used as the Time format.

    Returns:
      time_obj `Time`

        A new `Time` object corresponding to the input `time_string`.

  swapaxes(*args, **kwargs)

    Return an instance with the given axes interchanged.

    Parameters are as for `swapaxes()`: `axis1, axis2`. All internal data are views of the data of the original.

  take(indices, axis=None, out=None, mode='raise')

    Return a new instance formed from the elements at the given indices.

    Parameters are as for `take()`, except that, obviously, no output array can be given.

  to_datetime(timezone=None, leap_second_strict='raise')

    Convert to (potentially timezone-aware) `datetime` object.

    If `timezone` is not `None`, return a timezone-aware datetime object.

    Since the `datetime` class does not natively handle leap seconds, the behavior when converting a time within a leap second is controlled by the `leap_second_strict` argument. For example:

        >>> from astropy.time import Time
        >>> t = Time("2015-06-30 23:59:60.500")
        >>> print(t.to_datetime(leap_second_strict='silent'))
        2015-07-01 00:00:00.500000

    Parameters:
      timezone{`tzinfo`, `python:None`}, optional

        If not `None`, return timezone-aware datetime.

      leap_second_strict `python:str`, optional

        If `raise` (default), raise an exception if the time is within a leap second. If `warn` then issue a warning. If `silent` then silently handle the leap second.

    Returns:
      `datetime`

        If `timezone` is not `None`, output will be timezone-aware.

  to_string()

    Output a string representation of the Time or TimeDelta object.

    Similar to `str(self.value)` (which uses numpy array formatting) but array values are evaluated only for the items that actually are output. For large arrays this can be a substantial performance improvement.

    Returns:
      out `python:str`

        String representation of the time values.

  to_value(format, subfmt='*')

    Get time values expressed in specified output format.

    This method allows representing the `Time` object in the desired output `format` and optional sub-format `subfmt`. Available built-in formats include `jd`, `mjd`, `iso`, and so forth. Each format can have its own sub-formats

    For built-in numerical formats like `jd` or `unix`, `subfmt` can be one of ‘float’, ‘long’, ‘decimal’, ‘str’, or ‘bytes’. Here, ‘long’ uses `numpy.longdouble` for somewhat enhanced precision (with the enhancement depending on platform), and ‘decimal’ `decimal.Decimal` for full precision. For ‘str’ and ‘bytes’, the number of digits is also chosen such that time values are represented accurately.

    For built-in date-like string formats, one of ‘date_hms’, ‘date_hm’, or ‘date’ (or ‘longdate_hms’, etc., for 5-digit years in `TimeFITS`). For sub-formats including seconds, the number of digits used for the fractional seconds is as set by `precision`.

    Parameters:
      format `python:str`

        The format in which one wants the time values. Default: the current format.

      subfmt `python:str` or `python:None`, optional

        Value or wildcard pattern to select the sub-format in which the values should be given. The default of ‘*’ picks the first available for a given format, i.e., ‘float’ or ‘date_hms’. If `None`, use the instance’s `out_subfmt`.

  transpose(*args, **kwargs)

    Return an instance with the data transposed.

    Parameters are as for `transpose()`. All internal data are views of the data of the original.