Function from_compact 

pub fn from_compact(text: &str) -> Option<u64>

Reads a compact timestamp back.

The fraction may be absent or one to six digits, since a gateway that times to the millisecond writes three.

Arguments

• text - the timestamp, such as 2013-03-31T16:21:17.528002Z.

Returns

The time in microseconds since the epoch, or None when the text is not that shape or names no date on the calendar.