14 CFR §61.17

1. (a)A temporary pilot, flight instructor, or ground instructor certificate or rating is issued for up to 120 days, at which time a permanent certificate will be issued to a person whom the Administrator finds qualified under this part.
2. (b)A temporary pilot, flight instructor, or ground instructor certificate or rating expires:
   1. (1)On the expiration date shown on the certificate;
   2. (2)Upon receipt of the permanent certificate; or
   3. (3)Upon receipt of a notice that the certificate or rating sought is denied or revoked.