A temporary power distribution should last as strictly necessary for the event in question, and is typically intended for circuses, fairgrounds, festivals, outdoor shows and similar events. 
Check the documents needed to request a temporary power distribution here.

Requests for temporary power distribution should preferably be made 15 working days prior to the event's scheduled date.

The maximum length of time for a temporary power distribution is determined by an authorisation issued by the relevant administrative authority (e.g. City Council). 
You can check the mandatory requirements for a temporary power distribution here.