The B<tm_sec>, B<tm_min>, B<tm_hour>, B<tm_mday>, B<tm_wday>, B<tm_yday>,
B<tm_mon> and B<tm_year> fields of B<tm> structure are set to proper values,
whereas all other fields are set to 0. If B<tm> is NULL this function performs
-a format check on B<s> only.
+a format check on B<s> only. If B<s> is in Generalized format with franctional
+seconds, e.g. YYYYMMDDHHMMSS.SSSZ, the fractional seconds will be lost while
+converting B<s> to B<tm> structure.
ASN1_TIME_diff() sets B<*pday> and B<*psec> to the time difference between
B<from> and B<to>. If B<to> represents a time later than B<from> then