Friends, there’s never a good reason to include periodically in a contract.
Consider language of obligation:
The Bank will provide the Client periodically with a statement of account for each Account, identifying Assets held in the Accounts.
If I were the client, I’d sure want to be more specific that periodically, which could mean “at regular intervals” or just “from time to time.” I’d specify the intervals. And depending on the context, it might be appropriate instead to have the bank provide a statement whenever the client asks for one.
What about language of of discretion? Here’s an example:
The Trustees of the Trust may periodically review the commissions paid by the Portfolio to determine if the commissions paid over representative periods of time were reasonable in relation to the benefits to the Portfolio.
Presumably the idea is that the trustees would review commissions whenever they think it appropriate. The word periodically doesn’t express that.
And if you want to express the idea that stuff might change over time, you can do better than periodically:
… are in compliance with the Company’s written policies and procedures
in effect from time to time[then in effect], including the Code of Ethics & Business Conduct and the Guidelines on Significant Governance Issues , in each case as may be amended periodically…
and shall be determined by Agent in accordance with this Agreement and Agent’s loan systems and procedures
periodically[then] in effect …