# Source code for fontTools.misc.timeTools

    """fontTools.misc.timeTools.py -- tools for working with OpenType timestamps.
    """

    import os
    import time
    from datetime import datetime, timezone
    import calendar

    epoch_diff = calendar.timegm((1904, 1, 1, 0, 0, 0, 0, 0, 0))

    DAYNAMES = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    MONTHNAMES = [None, "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    			  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]

    def asctime(t=None):
    	"""
    	Convert a tuple or struct_time representing a time as returned by gmtime()
    	or localtime() to a 24-character string of the following form:

    	>>> asctime(time.gmtime(0))
    	'Thu Jan  1 00:00:00 1970'

    	If t is not provided, the current time as returned by localtime() is used.
    	Locale information is not used by asctime().

    	This is meant to normalise the output of the built-in time.asctime() across
    	different platforms and Python versions.
    	In Python 3.x, the day of the month is right-justified, whereas on Windows
    	Python 2.7 it is padded with zeros.

    	See https://github.com/fonttools/fonttools/issues/455
    	"""
    	if t is None:
    		t = time.localtime()
    	s = "%s %s %2s %s" % (
    		DAYNAMES[t.tm_wday], MONTHNAMES[t.tm_mon], t.tm_mday,
    		time.strftime("%H:%M:%S %Y", t))
    	return s

    def timestampToString(value):
    	return asctime(time.gmtime(max(0, value + epoch_diff)))

    def timestampFromString(value):
    	wkday, mnth = value[:7].split()
    	t = datetime.strptime(value[7:], ' %d %H:%M:%S %Y')
    	t = t.replace(month=MONTHNAMES.index(mnth), tzinfo=timezone.utc)
    	wkday_idx = DAYNAMES.index(wkday)
    	assert t.weekday() == wkday_idx, '"' + value + '" has inconsistent weekday'
    	return int(t.timestamp()) - epoch_diff

    def timestampNow():
    	# https://reproducible-builds.org/specs/source-date-epoch/
    	source_date_epoch = os.environ.get("SOURCE_DATE_EPOCH")
    	if source_date_epoch is not None:
    		return int(source_date_epoch) - epoch_diff
    	return int(time.time() - epoch_diff)

    def timestampSinceEpoch(value):
    	return int(value - epoch_diff)

    if __name__ == "__main__":
    	import sys
    	import doctest
    	sys.exit(doctest.testmod().failed)