@C. B. Zeller yes I believe that's the basis for this provision, and also assuming you've otherwise satisfied 1.461-1(a)(2) for accrual deductibility. I know I briefly worked on one pension plan that used this arrangement, but 20 years later I know I can't locate it. Otherwise, my wife was employed by Wyeth Pharmaceuticals, their pension would have determination letters and multiple audits over the years (it still survives today as the "Legacy" Pfizer Pension, albeit frozen since 2009).
@Luke Bailey @Peter Gulia no, I don't think the few weeks extended much past the first week of February, if that far. Based on payroll timing limits, the longest practice application would be end of January. Biggest reason for the delay that I can think of was for one-time deferral elections.
@BelgarathUltimately, no I don't think such a bonus would be part of the 2022 W-2, those regs are pretty clear that its paid within the limitation year only. Could it have practical applications to an employer allocation; yes. Could it be used in a projection; why not, I'll project whatever you pay me to. Could you use it to manipulate compensation basis for 401(a)(4) testing; maybe if you satisfied 461 accrual rules, felt it meet the 415 timing requirement, and passed 414.