- This Agreement shall be effective retroactive to January 1, 2011.
- This Agreement shall be effective on July 5, 2011
- This Agreement shall be effective on the date last signed by the parties
- This Agreement shall take effect on December 5,2012
- This Agreement shall be effective once all of the following conditions have been met
If the effective date is linked to the period for performance, there is always a possibility that a key date could slip, you could also work that into the term. For example: Contractor shall have One Hundred (100) calendar days after the Effective Date to complete all work. If Contractor is delayed in commencing performance by Owner, the period for performance shall be extended on a day for day basis."
The use of completion of conditions to establish the effective date is a form of condition precedent. Even if the Agreement is signed it isn't effective until those conditions have been met.