Pythonic formatting and parsing of ISO 8601 dates, times, and time zones.

iso8601_datetime.py

# This snippet demonstrates Pythonic formatting and parsing of ISO 8601 dates.

from datetime import datetime


# datetime.strptime() is used to parse iso 8601 strings to 
# Python datetime.datetime instances.

# datetime.strftime() is used to format Python datetime.datetime instances
# to ISO 8601 strings. 
# Note: the built-in function, format() calls datetime.strftime().


# YYYY
d = datetime.strptime("2020", "%Y")
print(format(d, "%Y"))


# YYYY-MM
d = datetime.strptime("2020-05", "%Y-%m")
print(format(d, "%Y-%m"))


# YYYY-MM-DD
d = datetime.strptime("2020-05-03", "%Y-%m-%d")
print(format(d, "%F"))
# Note: the shortcut %F directive is supported by strftime(),
# but not strptime()!


# hh:mm
d = datetime.strptime("13:15", "%H:%M")
print(format(d, "%R"))
# Note: the shortcut %R directive is supported by strftime(),
# but not strptime()!


# hh:mm:ss
d = datetime.strptime("13:15:45", "%H:%M:%S")
print(format(d, "%T"))
# Note: the shortcut %T directive is supported by strftime(),
# but not strptime()!


# hh:mm:ss.sss
d = datetime.strptime("13:15:45.321", "%H:%M:%S.%f")
print(format(d, "%T.%f")[:-3])


# hh:mm:ssZ (zulu time)
d = datetime.strptime("13:15:45", "%H:%M:%S")
print(format(d, "%H:%M:%SZ"))


# Create a datetime for time zone formats below.
d = datetime.strptime("13:15:45-08:30", "%H:%M:%S%z")

# Have to do a little work here to achieve time zone offsets with either
# Simple hh (hours only) or the extended hh:mm format.
s = format(d, "%T%z")
s1 = s[:11]
s2 = s[11:]

# hh:mm:ss±hh
print(s1)

# hh:mm:ss±hh:mm
print(s1+":"+s2)


# YYYY-MM-DDThh:mm:ss-hh:ss (full date/time/time zone)
d = datetime.strptime("2020-05-03T13:15:45-08:30", "%Y-%m-%dT%H:%M:%S%z")
print(format(d, "%F") + "T" + s1 + ":" + s2)