mjd

#!/usr/bin/python
from astropy.time import Time
import datetime
import sys


helper = """
Calculate and convert MJDs

If no argument is supplied, will return the MJD now.
Can otherwise supply:
-a date in YYYY-MM-DD format
-a time in YYYY-MM-DD HH:MM:SS format
-an MJD to convert to a datetime
"""

if len(sys.argv) == 1:
    now = datetime.datetime.utcnow()
    t = Time(now)
    print(now,"->",t.mjd)
else:
    if sys.argv[1] == "-h" or sys.argv[1] == "--help" or sys.argv[1] == "help":
        print(helper)
    elif len(sys.argv) == 3 and "-" in sys.argv[1] and ":" in sys.argv[2]:
        t = Time(datetime.datetime.strptime(sys.argv[1]+" "+sys.argv[2],"%Y-%m-%d %H:%M:%S"))
        print("%s -> %i"%(t.datetime,t.mjd))
    elif "-" in sys.argv[1]:
        t = Time(datetime.datetime.strptime(sys.argv[1],"%Y-%m-%d"))
        print("%s -> %i"%(t.datetime,t.mjd))
    else:
        t = Time(float(sys.argv[1]),scale='utc',format='mjd')
        print("%i -> %s"%(t.mjd,repr(t.datetime)))