Standard FME Date/Time Format

Date/Time Terminology

Temporal value/type:

Date: A calendar date.
Time: A clock time, optionally with a UTC offset.
Datetime: A calendar date together with a clock time, optionally with a UTC offset.

Note: For convenience, Datetime is often used as a synonym of temporal value.

Interval: A period of time between two temporal values. Example: Date + interval.

The standard FME format for date, time, and datetime values is:

Example: 20170206

Example: 111730, 111730.135

Example: 111730.135-08:00

Example: 20170206111730.135

Example: 20170206111730.135-08:00

Any date/time value in the above syntax, and which corresponds to a real point in time, is considered valid.
Invalid date/time values include:

Where	Description	Example
yyyy	4-digit year	2011
mm	2-digit month	07
dd	2-digit day of month	05
hh	2-digit hour of a 24-hour clock	14
mm	2-digit minutes	02
ss	2-digit seconds	59
.123456789	Optional fraction of a second, up to 9 digits or nanosecond resolution. Additional fractional digits are accepted, but only 9 fractional digits are kept during temporal arithmetic. Trailing zeros in the fractional digits are automatically trimmed. Only the "`.`" character is recognized as the decimal separator, even on systems where it is not the default decimal separator.	140259.135
UTC offset	Timezone offset with syntax [+\|-]hh:mm (default), [+\|-]hhmm, or [+\|-]hh. Note: It is a common mistake to misinterpret how UTC offsets are applied. For example, 8PM-08:00 (Pacific Standard Time) is equivalent to 11PM-05:00 (Eastern Standard Time). To get the UTC times, add the negated UTC offset to the unzoned times: 8PM+08:00 = 4AM the next day, and 11PM+05:00 = 4AM the next day. Therefore, @DateTimeDiff(200000-08:00,230000-05:00) = PT0S, meaning the two times are identical in terms of UTC time.	+00:00 -08:00 -08

The FME interval format is based on the ISO 8601 duration format:

Example: -P1Y2M3DT4H5M6.123456789S
The "-" sign indicates a negative interval.
P is a delimiter character meaning "Period".
Y = year, M = month, D = day, T = delimiter disambiguating month and minutes, H = hours, M = minutes, and S = seconds.
Only the seconds field is a floating point value. The other fields are integers.
The delimiters P, Y, M, D, T, H, M, and S must occur in that order. So, P1M1Y is invalid.
If a field has the value 0, it is omitted. If all fields have value 0, PT0S is returned.
All fields must be positive, unless all fields are zero. The "-" sign specifies a negative interval.