directives for strptime/strftime
reference date time: 2019-06-07 07:03:12.234394
year 2019 %Y
year, 2-digits, zero-padded 19 %y
month full name (locale specific) June %B
month abbreviated name (locale specific) Jun %b
month, zero-padded 06 %m
day of the month, zero-padded 07 %d
day of the year, zero-padded 158 %j
hour, 24h clock, zero-padded 07 %H
hour, 12h clock, zero-padded 07 %I
minute, zero-padded 03 %M
second, zero-padded 12 %S
microsecond, zero-padded 234394 %f
AM/PM (locale specific) AM %p
time zone name UTC %Z
UTC offset in the form ±HHMM[SS[.ffffff]] +0000 %z
weekday full name (locale specific) Friday %A
weekday abbreviated name (locale specific) Fri %a
weekday as a number Sunday is 0 5 %w
week number of the year, zero-padded, Monday first day 22 %W
week number of the year, zero-padded Sunday first day 22 %U
locale representation for time/date/datetime
time representation 07:03:12 %X
date representation 06/07/19 %x
datetime representation Fri Jun 7 07:03:12 2019 %c
ISO 8601 year 2019 %G
ISO 8601 weekday 5 %u
ISO 8601 week number, Monday first day 23 %V
extra