Deposit Timing of Prevailing Wage Contributions

[Guest dossrocks]

A client of ours does a lot of work of on prevailing wage jobs. They have a 401k/PS plan and contribute the prevaling wage contributions to the plan. They are also known to make untimely 401k deposits and possibly prevailing wage contributions. I've been doing some reading on prevailing wage and maybe I'm thinking too much into it but am a little confused as to the timing of the deposits. The most common answer that I've seen is that the prevaling wage contribution submitted to a qualifed retirement plan must be made at least quarterly.

My question is that if you have a paydate in January which contains prevaling wage I understand that the prevailing wage contributions must be made to the plan no later than March 31st but what if your pay period is the middle of March. Do those prevaling wage contributions from March also have be submitted to the plan by March 31st? Must all prevailing wage contributions within a quarter regardless of the paydate be submitted by the end of that quarter?