Use this tag for questions related to the Datetime conversion, i.e. manipulating the Datetime in such a way, that a new, different in format, Datetime is produced.
datetime-conversion is used in its general meaning, and is usually used for questions related on how to convert a Datetime object in another, new and with a different format, Datetime object, usually for making two different programming platforms communicate.
For example, your application may produce Datetimes of a specific format, but your Database to accept another Datetime format, different from the one your application is using. In that case, a conversion form the application's format to the Database's format is needed.