In regards to the actual timing of a Paschal – Last Supper event;
“So important is it to have a clear understanding of all that passed on that occasion, that at the risk of some repetition, we shall now attempt to piece together the notices in the various Gospels, adding to them again those explanations which have just been given in detail. At the outset we may dismiss, an unworthy of serious discussion, the theory, either that our Lord had observed the Paschal Supper at another than the regular time for it, or that St. John meant to intimate that He had partaken of it on the 13th instead of the 14th of Nisan.
To such violent hypothesis, which are wholly uncalled for, there is this one conclusive answer, that except on the evening of the 14th of Nisan, no Paschal lamb could have been offered in the temple, and therefore no Paschal Supper celebrated in Jerusalem.” [End Quote]
The Temple, Its Ministry and Services as they were At The Time Of Jesus Christ. (1874)
Chapter XII ‘The Paschal Feast And The Lord’s Supper, Rev. Dr. Alfred Edersheim
In Regards to the timing of the Pascal - Last Supper Event (continued);
“ In attempting an accurate chronology of these days (Pesach) it must always be remembered that the Passover was sacrificed between the evenings of the 14th and the 15th of Nisan ; that is, before the close of the 14th and the beginning of the 15th. The Paschal Supper, however took place on the 15th itself (that is according to Jewish reckoning – the day beginning as the first stars became visible).” [End Quote]
The Temple, Its Ministry and Services as they were At The Time Of Jesus Christ. (1874)
Chapter XI ‘The Passover, Rev. Dr. Alfred Edersheim