When calculating the time for performance under the promulgated forms, is the effective date included as the first day?

No. Here is an example: The buyer has the right to terminate the contract within five days after the effective date, and the effective date is January 1. The buyer may terminate the contract at any time until 5 p.m. on January 6. Note that January 2 is the first day after the effective date.

Source: TAR