Functions that require a date-time to be specified in ISO 8601 format (<iso-date-string>) will accept the following formats.
Year: YYYY (eg 2013, defaults to 2013-01-01) Year and month: YYYY-MM (eg 2013-07, defaults to 2013-07-01) Complete date: YYYY-MM-DD (eg 2013-07-16) Complete date plus hours with optional "Z": YYYY-MM-DDThh (eg 2013-07-16T19, defaults to 2013-07-16T19:00:00Z) YYYY-MM-DDThhZ (eg 2013-07-16T19Z, defaults to 2013-07-16T19:00:00Z) Complete date plus hours and minutes with optional "Z": YYYY-MM-DDThh:mm (eg 2013-07-16T19:23, defaults to 2013-07-16T19:23:00Z) YYYY-MM-DDThh:mmZ (eg 2013-07-16T19:23Z, defaults to 2013-07-16T19:23:00Z) Complete date plus hours, minutes and seconds with optional "Z": YYYY-MM-DDThh:mm:ss (eg 2013-07-16T19:23:51, defaults to 2013-07-16T19:23:51Z) YYYY-MM-DDThh:mm:ssZ (eg 2013-07-16T19:23:51Z)
where
YYYY = four-digit year
MM = two-digit month (01=January, etc.)
DD = two-digit day of month (01 through 31)
hh = two digits of hour (00 through 23) (am/pm NOT allowed)
mm = two digits of minute (00 through 59)
ss = two digits of second (00 through 59)
Z = special UTC designator ("Z") (optional)
Times are always interpreted as GMT (UTC) times regardless of whether a "Z" time zone designator is appended or not. Time zone designators of the form "+hh:mm" are not accepted. Years before 1900 are not accepted (so, sorry, no X.509 certs for Julius Caesar). Be careful, if you examine the resulting files in another time zone using other tools, like Windows Certificate Manager, the times may display differently in local time. This is not an error.