The special apparently doesn't have to be paid until the end of January, as long as it is declared prior by 12/31. I assume the record date has to be in 1999 also. Unlike the "regular" dividend, the payment can't be delayed beyond that date.
As far as bank covenants go, it would be relatively easy for the banks to waive the covenant (if it applies) and instead switch it to regular dividends. The remaining cash for the special is less than a regular quarterly dividend, so the banks should be fine with it.