gistfile1.txt

from pyrap.quanta import quantity
import time

# Unix time starts at 00:00:00 coordinated universal time on 1 January 1970.
unix_epoch = quantity("1970-01-01T00:00:00")

def unix_to_mjds(unix_time):
    return unix_time + unix_epoch.get_value('s')

def mjds_to_unix(mjds):
    return mjds - unix_epoch.get_value('s')

def s2d(seconds):
    # seconds to days
    return seconds / (24 * 60 * 60.0)

def d2s(days):
    # days to seconds
    return days * (24 * 60 * 60.0)

if __name__ == "__main__":
    print "The Unix epoch starts when MJD is %d seconds" % (
          unix_epoch.get_value('s'))

    now_unix = time.time()
    print "\nThe current Unix time is %d" % (now_unix,)
    print "That's equivalent to an MJD of %f s (%f d)" % (
          unix_to_mjds(now_unix), s2d(unix_to_mjds(now_unix)))

    now_pyrap = quantity('today').get_value('s')
    print "\nThe current MJD is %f s (%f d)" % (
           now_pyrap, now_pyrap / (24 * 3600))
    print "That's equivalent to a unix time of %d" % (
           mjds_to_unix(now_pyrap),)