vrillusions/rfc3339-iso8601

RFC 3339 vs. ISO 8601

Comparison between some valid RFC 3339 and ISO 8601 date formats

Notes:

• This table is not exhaustive.
• Both formats are case-insensitive so every T, W, P, R, and Z could be t, w, p, r, or z respectively.
• RFC 3339 allows for other characters to replace the T but only gives examples using a space character.
• ISO 8601 allows decimal fractions for the smallest time value. These are just represented by ,5 and .5 due to a limitation of the formatter.
• ISO 8601 prefers commas to dots for decimal separation but they are interchangeable in all formats.
• The format key is given below the table.

Format	Now	RFC 3339	ISO 8601
%Y-%m-%d %H:%M:%SZ	2021-07-27 14:20:32Z	✔️
%Y-%m-%d_%H:%M:%SZ	2021-07-27_14:20:32Z	✔️
%Y-%m-%d %H:%M:%Sz	2021-07-27 14:20:32z	✔️
%Y-%m-%d_%H:%M:%Sz	2021-07-27_14:20:32z	✔️
%Y-%m-%d %H:%M:%S.%UZ	2021-07-27 14:20:32.556Z	✔️
%Y-%m-%d_%H:%M:%S.%UZ	2021-07-27_14:20:32.556Z	✔️
%Y-%m-%d %H:%M:%S.%Uz	2021-07-27 14:20:32.556z	✔️
%Y-%m-%d_%H:%M:%S.%Uz	2021-07-27_14:20:32.556z	✔️
%Y-%m-%d %H:%M:%S-00:00	2021-07-27 14:20:32-00:00	✔️
%Y-%m-%d %H:%M:%S.%U-00:00	2021-07-27 14:20:32.556-00:00	✔️
%Y-%m-%dT%H:%M:%S-00:00	2021-07-27T14:20:32-00:00	✔️
%Y-%m-%dT%H:%M:%S.%U-00:00	2021-07-27T14:20:32.556-00:00	✔️
%Y-%m-%d	2021-07-27	✔️	✔️
%H:%M:%SZ	14:20:32Z	✔️	✔️
%Y-%m-%dT%H:%M:%SZ	2021-07-27T14:20:32Z	✔️	✔️
%Y-%m-%dT%H:%M:%S.%UZ	2021-07-27T14:20:32.556Z	✔️	✔️
%Y-%m-%dT%H:%M:%S+00:00	2021-07-27T14:20:32+00:00	✔️	✔️
%Y-%m-%dT%H:%M:%S.%U+00:00	2021-07-27T14:20:32.556+00:00	✔️	✔️
%Y-%m-%dT%H:%M:%S%Z:%z	2021-07-27T22:20:32+08:00	✔️	✔️
%Y-%m-%dT%H:%M:%S.%U%Z:%z	2021-07-27T22:20:32.556+08:00	✔️	✔️
%Y-%m-%dT%H:%M:%S-04:00	2021-07-27T10:20:32-04:00	✔️	✔️
%Y-%m-%dT%H:%M:%S.%U-04:00	2021-07-27T10:20:32.556-04:00	✔️	✔️
%Y-%m-%dT%H−04:00	2021-07-27T10−04:00		✔️
%Y-%m-%dT%H:%M−04:00	2021-07-27T10:20−04:00		✔️
%Y-%m-%dT%H:%M:%S−04:00	2021-07-27T10:20:32−04:00		✔️
%Y-%m-%dT%H:%M:%S,%U−04:00	2021-07-27T10:20:32,556−04:00		✔️
%Y-%m-%dT%H:%M:%S.%U−04:00	2021-07-27T10:20:32.556−04:00		✔️
%C	20		✔️
%Y	2021		✔️
%Y-%m	2021-07		✔️
%Y-%o	2021-208		✔️
%Y-W%W	2021-W30		✔️
%Y-W%W-%w	2021-W30-2		✔️
%Y%o	2021208		✔️
%YW%W	2021W30		✔️
%YW%W%w	2021W302		✔️
%H	22		✔️
%H,5	22,5		✔️
%H.5	22.5		✔️
%H:%M	22:20		✔️
%H:%M,5	22:20,5		✔️
%H:%M.5	22:20.5		✔️
%H:%M:%S	22:20:32		✔️
%H:%M:%S,%U	22:20:32,556		✔️
%H:%M:%S.%U	22:20:32.556		✔️
T%H	T22		✔️
T%H,5	T22,5		✔️
T%H.5	T22.5		✔️
T%H:%M	T22:20		✔️
T%H:%M,5	T22:20,5		✔️
T%H:%M.5	T22:20.5		✔️
T%H:%M:%S	T22:20:32		✔️
T%H:%M:%S,%U	T22:20:32,556		✔️
T%H:%M:%S.%U	T22:20:32.556		✔️
%Y-%m-%dT%H	2021-07-27T22		✔️
%Y-%m-%dT%H,5	2021-07-27T22,5		✔️
%Y-%m-%dT%H.5	2021-07-27T22.5		✔️
%Y-%m-%dT%H:%M	2021-07-27T22:20		✔️
%Y-%m-%dT%H:%M,5	2021-07-27T22:20,5		✔️
%Y-%m-%dT%H:%M.5	2021-07-27T22:20.5		✔️
%Y-%m-%dT%H:%M:%S	2021-07-27T22:20:32		✔️
%Y-%m-%dT%H:%M:%S,%U	2021-07-27T22:20:32,556		✔️
%Y-%m-%dT%H:%M:%S.%U	2021-07-27T22:20:32.556		✔️
%G-W%W-%wT%H	2021-W30-2T22		✔️
%G-W%W-%wT%H,5	2021-W30-2T22,5		✔️
%G-W%W-%wT%H.5	2021-W30-2T22.5		✔️
%G-W%W-%wT%H:%M	2021-W30-2T22:20		✔️
%G-W%W-%wT%H:%M,5	2021-W30-2T22:20,5		✔️
%G-W%W-%wT%H:%M.5	2021-W30-2T22:20.5		✔️
%G-W%W-%wT%H:%M:%S	2021-W30-2T22:20:32		✔️
%G-W%W-%wT%H:%M:%S,%U	2021-W30-2T22:20:32,556		✔️
%G-W%W-%wT%H:%M:%S.%U	2021-W30-2T22:20:32.556		✔️
%Y-%oT%H	2021-208T22		✔️
%Y-%oT%H,5	2021-208T22,5		✔️
%Y-%oT%H.5	2021-208T22.5		✔️
%Y-%oT%H:%M	2021-208T22:20		✔️
%Y-%oT%H:%M,5	2021-208T22:20,5		✔️
%Y-%oT%H:%M.5	2021-208T22:20.5		✔️
%Y-%oT%H:%M:%S	2021-208T22:20:32		✔️
%Y-%oT%H:%M:%S,%U	2021-208T22:20:32,556		✔️
%Y-%oT%H:%M:%S.%U	2021-208T22:20:32.556		✔️
%Y%m%dT%H	20210727T22		✔️
%Y%m%dT%H,5	20210727T22,5		✔️
%Y%m%dT%H.5	20210727T22.5		✔️
%Y%m%dT%H%M	20210727T2220		✔️
%Y%m%dT%H%M,5	20210727T2220,5		✔️
%Y%m%dT%H%M.5	20210727T2220.5		✔️
%Y%m%dT%H%M%S	20210727T222032		✔️
%Y%m%dT%H%M%S,%U	20210727T222032,556		✔️
%Y%m%dT%H%M%S.%U	20210727T222032.556		✔️
%GW%W%wT%H	2021W302T22		✔️
%GW%W%wT%H,5	2021W302T22,5		✔️
%GW%W%wT%H.5	2021W302T22.5		✔️
%GW%W%wT%H%M	2021W302T2220		✔️
%GW%W%wT%H%M,5	2021W302T2220,5		✔️
%GW%W%wT%H%M.5	2021W302T2220.5		✔️
%GW%W%wT%H%M%S	2021W302T222032		✔️
%GW%W%wT%H%M%S,%U	2021W302T222032,556		✔️
%GW%W%wT%H%M%S.%U	2021W302T222032.556		✔️
%Y%oT%H	2021208T22		✔️
%Y%oT%H,5	2021208T22,5		✔️
%Y%oT%H.5	2021208T22.5		✔️
%Y%oT%H%M	2021208T2220		✔️
%Y%oT%H%M,5	2021208T2220,5		✔️
%Y%oT%H%M.5	2021208T2220.5		✔️
%Y%oT%H%M%S	2021208T222032		✔️
%Y%oT%H%M%S,%U	2021208T222032,556		✔️
%Y%oT%H%M%S.%U	2021208T222032.556		✔️
%Y-%m-%dT%H%Z	2021-07-27T22+08		✔️
%Y-%m-%dT%H,5%Z	2021-07-27T22,5+08		✔️
%Y-%m-%dT%H.5%Z	2021-07-27T22.5+08		✔️
%Y-%m-%dT%H:%M%Z	2021-07-27T22:20+08		✔️
%Y-%m-%dT%H:%M,5%Z	2021-07-27T22:20,5+08		✔️
%Y-%m-%dT%H:%M.5%Z	2021-07-27T22:20.5+08		✔️
%Y-%m-%dT%H:%M:%S%Z	2021-07-27T22:20:32+08		✔️
%Y-%m-%dT%H:%M:%S,%U%Z	2021-07-27T22:20:32,556+08		✔️
%Y-%m-%dT%H:%M:%S.%U%Z	2021-07-27T22:20:32.556+08		✔️
%G-W%W-%wT%H%Z	2021-W30-2T22+08		✔️
%G-W%W-%wT%H,5%Z	2021-W30-2T22,5+08		✔️
%G-W%W-%wT%H.5%Z	2021-W30-2T22.5+08		✔️
%G-W%W-%wT%H:%M%Z	2021-W30-2T22:20+08		✔️
%G-W%W-%wT%H:%M,5%Z	2021-W30-2T22:20,5+08		✔️
%G-W%W-%wT%H:%M.5%Z	2021-W30-2T22:20.5+08		✔️
%G-W%W-%wT%H:%M:%S%Z	2021-W30-2T22:20:32+08		✔️
%G-W%W-%wT%H:%M:%S,%U%Z	2021-W30-2T22:20:32,556+08		✔️
%G-W%W-%wT%H:%M:%S.%U%Z	2021-W30-2T22:20:32.556+08		✔️
%Y-%oT%H%Z	2021-208T22+08		✔️
%Y-%oT%H,5%Z	2021-208T22,5+08		✔️
%Y-%oT%H.5%Z	2021-208T22.5+08		✔️
%Y-%oT%H:%M%Z	2021-208T22:20+08		✔️
%Y-%oT%H:%M,5%Z	2021-208T22:20,5+08		✔️
%Y-%oT%H:%M.5%Z	2021-208T22:20.5+08		✔️
%Y-%oT%H:%M:%S%Z	2021-208T22:20:32+08		✔️
%Y-%oT%H:%M:%S,%U%Z	2021-208T22:20:32,556+08		✔️
%Y-%oT%H:%M:%S.%U%Z	2021-208T22:20:32.556+08		✔️
%Y%m%dT%H%Z	20210727T22+08		✔️
%Y%m%dT%H,5%Z	20210727T22,5+08		✔️
%Y%m%dT%H.5%Z	20210727T22.5+08		✔️
%Y%m%dT%H%M%Z	20210727T2220+08		✔️
%Y%m%dT%H%M,5%Z	20210727T2220,5+08		✔️
%Y%m%dT%H%M.5%Z	20210727T2220.5+08		✔️
%Y%m%dT%H%M%S%Z	20210727T222032+08		✔️
%Y%m%dT%H%M%S,%U%Z	20210727T222032,556+08		✔️
%Y%m%dT%H%M%S.%U%Z	20210727T222032.556+08		✔️
%GW%W%wT%H%Z	2021W302T22+08		✔️
%GW%W%wT%H,5%Z	2021W302T22,5+08		✔️
%GW%W%wT%H.5%Z	2021W302T22.5+08		✔️
%GW%W%wT%H%M%Z	2021W302T2220+08		✔️
%GW%W%wT%H%M,5%Z	2021W302T2220,5+08		✔️
%GW%W%wT%H%M.5%Z	2021W302T2220.5+08		✔️
%GW%W%wT%H%M%S%Z	2021W302T222032+08		✔️
%GW%W%wT%H%M%S,%U%Z	2021W302T222032,556+08		✔️
%GW%W%wT%H%M%S.%U%Z	2021W302T222032.556+08		✔️
%Y%oT%H%Z	2021208T22+08		✔️
%Y%oT%H,5%Z	2021208T22,5+08		✔️
%Y%oT%H.5%Z	2021208T22.5+08		✔️
%Y%oT%H%M%Z	2021208T2220+08		✔️
%Y%oT%H%M,5%Z	2021208T2220,5+08		✔️
%Y%oT%H%M.5%Z	2021208T2220.5+08		✔️
%Y%oT%H%M%S%Z	2021208T222032+08		✔️
%Y%oT%H%M%S,%U%Z	2021208T222032,556+08		✔️
%Y%oT%H%M%S.%U%Z	2021208T222032.556+08		✔️
%Y-%m-%dT%H%Z:%z	2021-07-27T22+08:00		✔️
%Y-%m-%dT%H,5%Z:%z	2021-07-27T22,5+08:00		✔️
%Y-%m-%dT%H.5%Z:%z	2021-07-27T22.5+08:00		✔️
%Y-%m-%dT%H:%M%Z:%z	2021-07-27T22:20+08:00		✔️
%Y-%m-%dT%H:%M,5%Z:%z	2021-07-27T22:20,5+08:00		✔️
%Y-%m-%dT%H:%M.5%Z:%z	2021-07-27T22:20.5+08:00		✔️
%Y-%m-%dT%H:%M:%S,%U%Z:%z	2021-07-27T22:20:32,556+08:00		✔️
%G-W%W-%wT%H%Z:%z	2021-W30-2T22+08:00		✔️
%G-W%W-%wT%H,5%Z:%z	2021-W30-2T22,5+08:00		✔️
%G-W%W-%wT%H.5%Z:%z	2021-W30-2T22.5+08:00		✔️
%G-W%W-%wT%H:%M%Z:%z	2021-W30-2T22:20+08:00		✔️
%G-W%W-%wT%H:%M,5%Z:%z	2021-W30-2T22:20,5+08:00		✔️
%G-W%W-%wT%H:%M.5%Z:%z	2021-W30-2T22:20.5+08:00		✔️
%G-W%W-%wT%H:%M:%S%Z:%z	2021-W30-2T22:20:32+08:00		✔️
%G-W%W-%wT%H:%M:%S,%U%Z:%z	2021-W30-2T22:20:32,556+08:00		✔️
%G-W%W-%wT%H:%M:%S.%U%Z:%z	2021-W30-2T22:20:32.556+08:00		✔️
%Y-%oT%H%Z:%z	2021-208T22+08:00		✔️
%Y-%oT%H,5%Z:%z	2021-208T22,5+08:00		✔️
%Y-%oT%H.5%Z:%z	2021-208T22.5+08:00		✔️
%Y-%oT%H:%M%Z:%z	2021-208T22:20+08:00		✔️
%Y-%oT%H:%M,5%Z:%z	2021-208T22:20,5+08:00		✔️
%Y-%oT%H:%M.5%Z:%z	2021-208T22:20.5+08:00		✔️
%Y-%oT%H:%M:%S%Z:%z	2021-208T22:20:32+08:00		✔️
%Y-%oT%H:%M:%S,%U%Z:%z	2021-208T22:20:32,556+08:00		✔️
%Y-%oT%H:%M:%S.%U%Z:%z	2021-208T22:20:32.556+08:00		✔️
%Y%m%dT%H%Z%z	20210727T22+0800		✔️
%Y%m%dT%H,5%Z%z	20210727T22,5+0800		✔️
%Y%m%dT%H.5%Z%z	20210727T22.5+0800		✔️
%Y%m%dT%H%M%Z%z	20210727T2220+0800		✔️
%Y%m%dT%H%M,5%Z%z	20210727T2220,5+0800		✔️
%Y%m%dT%H%M.5%Z%z	20210727T2220.5+0800		✔️
%Y%m%dT%H%M%S%Z%z	20210727T222032+0800		✔️
%Y%m%dT%H%M%S,%U%Z%z	20210727T222032,556+0800		✔️
%Y%m%dT%H%M%S.%U%Z%z	20210727T222032.556+0800		✔️
%GW%W%wT%H%Z%z	2021W302T22+0800		✔️
%GW%W%wT%H,5%Z%z	2021W302T22,5+0800		✔️
%GW%W%wT%H.5%Z%z	2021W302T22.5+0800		✔️
%GW%W%wT%H%M%Z%z	2021W302T2220+0800		✔️
%GW%W%wT%H%M,5%Z%z	2021W302T2220,5+0800		✔️
%GW%W%wT%H%M.5%Z%z	2021W302T2220.5+0800		✔️
%GW%W%wT%H%M%S%Z%z	2021W302T222032+0800		✔️
%GW%W%wT%H%M%S,%U%Z%z	2021W302T222032,556+0800		✔️
%GW%W%wT%H%M%S.%U%Z%z	2021W302T222032.556+0800		✔️
%Y%oT%H%Z%z	2021208T22+0800		✔️
%Y%oT%H,5%Z%z	2021208T22,5+0800		✔️
%Y%oT%H.5%Z%z	2021208T22.5+0800		✔️
%Y%oT%H%M%Z%z	2021208T2220+0800		✔️
%Y%oT%H%M,5%Z%z	2021208T2220,5+0800		✔️
%Y%oT%H%M.5%Z%z	2021208T2220.5+0800		✔️
%Y%oT%H%M%S%Z%z	2021208T222032+0800		✔️
%Y%oT%H%M%S,%U%Z%z	2021208T222032,556+0800		✔️
%Y%oT%H%M%S.%U%Z%z	2021208T222032.556+0800		✔️

%C - Century
%Y - Year
%m - Month
%d - Day
%G - Week Year
%W - Week
%w - Week Day
%o - Ordinal Day

%H - Hour
%M - Minute
%S - Second
%U - Millisecond

%Z - Zone Hour including +/-
%z - Zone Minute