43 CFR §3475.3

1. (a)Leases will be dated and made effective the first day of the month following the date signed by the authorized officer. However, upon receipt of a prior written request, the authorized officer may date a lease to be effective on the first day of the month in which it is signed.
2. (b)Future interest leases shall become effective on the date of vesting of title to the minerals in the United States as stated in the lease.