ASN1_TIME_to_tm() converts the time B<s> to the standard B<tm> structure.
If B<s> is NULL, then the current time is converted. The output time is GMT.
-Only the B<tm_sec>, B<tm_min>, B<tm_hour>, B<tm_mday>, B<tm_mon> and B<tm_year>
-fields are updated.
+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.
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