Rangers have disclosed that the controversial 27 April date for the final Old Firm match of the season had been pencilled in as far back as August.
Ian McLeod and John McClelland disagreed over the fixture date
Celtic on Wednesday withdrew their protest at the fixture scheduling after originally describing the decision made by a majority of the Scottish Premier League's 12 chairmen as unfair and biased.
Strathclyde Police had told Celtic that the date should stand in the interests of public safety as delaying it any further risked making it the kind of title decider that has caused violence between the clubs' fans in the past.
And Rangers chairman John McClelland told his club's website: "April 27th has been assumed as the date of this fixture since at least last August in relation to television scheduling and Rangers FC was notified by the SPL at that time."
The date could only be confirmed once it was known last weekend which teams would play their remaining games in the top-six section of the SPL.
But Celtic had claimed that there was a "sporting imbalance" in asking them to play such an important league game just three days after their Uefa Cup semi-final second leg tie against Boavista in Portugal.
Rangers, apart from backing 27 April in last week's vote, had publically remained aloof from the argument until Celtic's dramatic U-turn.
The behaviour of the Celtic chief executive has been totally reprehensible
Rangers fans' leader John McMillan
"Rangers FC is pleased that the date of this season's remaining Old Firm game has been confirmed, allowing football clubs and their supporters to proceed with preparing for this season's remaining fixtures," said McClelland.
"The weekend of 27 April was the only remaining date which could not be a potential league title decider and was therefore the only viable option for this fixture in light of public safety concerns as outlined by Strathclyde Police and backed by the SPL's vote."
Celtic had gone as far as to claim that, despite this website and BBC television carrying a police statement to that effect on Friday, that they did not know of police backing for the SPL vote until Wednesday morning.
But McClelland pointed out: "The principal of avoiding the last Old Firm game as a league decider is a well-established one and has been previously accepted by all clubs."
Rangers supporters chief John McMillan went further, suggesting that Celtic chief executive Ian McLeod should be punished for originally suggesting that the SPL vote could cause trouble because Celtic fans would be left with a sense of injustice.
"The behaviour of the Celtic chief executive has been totally reprehensible," he said.
"Something has to be done about this.
"He made some serious allegations when he talks about institutional discrimination and bias."