Radios and calculators at the ready then. Come 4.00 or thereabouts, there will be no turning back and no second chances. The permutations will be over and make-up of all the semi-finals, relegation and promotion places and the relegation/promotion play-offs will be known.
For nine clubs in the AIB League first division, and another eight clubs in the second division, not to mention Sligo and Midleton (who are playing for All-Ireland League status in a play-off in Portlaoise) there is still something tangible at stake.
It's worth repeating the point that were it not for the advent of the top four play-offs in Division One, then the league title would already be decided and again residing in Shannon. As usual, the league would have had an anti-climactic finale. While it's a bit rough on the holders, this is an altogether more exciting scenario.
Take Clifford Park this afternoon, where the RTE cameras and the biggest crowd of the day will be present for the Limerick derby between Young Munster and Old Crescent. Normally, this game would only have mattered to the relegation-threatened visitors and a few diehards.
Granted, the usual quotient of local pride would be at stake - a `nothing' Limerick derby is a contradiction in terms. However, not only are Crescent fighting for their Division One lives, but though they are already assured of a place in the play-offs, Munsters have the very real carrot of a home semi-final to play for. That scenario would also entail second-placed Garryowen losing at home to Ballymena, whose hopes of squeezing into the top four rest with St Mary's slipping up at relegated Old Belvedere.
Given they are arguably the best-supported club in the country, with a membership alone of over 1,000, this is something that will transmit itself to the Munsters' dressingroom. "A home semi-final would be massive for the club," maintains the team manager John `Packo' Fitzgerald. Crescent currently occupy a place which would leave them having to play off to ensure they stay in Division One, while just behind them in the third automatic relegation spot are a Dolphin side who entertain Lansdowne, themselves not sure of avoiding the play-offs. Dolphin know they can overtake Lansdowne by winning by 28 points or more.
Blackrock, who entertain midtable Cork Constitution, are also not safe - defeat could see them ensnared in a relegation play-off, which would have the curious side effect of pitting George Hook (coach at Blackrock) against his long-time friend and coaching protege Eddie O'Sullivan (coach at Buccaneers).
Dungannon, second from bottom, must beat Clontarf at home to have any hope of survival via the relegation play-off with the second-placed side in Division Two. Even that may not be enough, and the likeliest outcome is that Dungannon and Crescent will accompany Old Belvedere into Division Two, with Buccaneers engaging Dolphin in a two-legged play-off.
Buccaneers still look likely to finish as runners-up in Division Two, presuming Galwegians complete a 100 per cent season by winning at Malone. The Belfast club are one of six clubs in the second flight involved in a convoluted, last-day relegation dogfight. Away from matters AIL, the Irish Youths (another of Irish rugby's underage success stories in recent times) seek to continue their 100 per cent record this season against Scotland at Ravenhill after wins over Italy and Wales augmented last season's defeats of Scotland and Wales.
Boldly going into terrain where others (notably the Schools' teams) have rarely gone before, the Youths have already produced the likes of Trevor Brennan, Shane Horgan and Mark McHugh. They look set to become the most important conveyor belt in the system.
The Irish Schools are also hoping to set up a Triple Crown decider against their English counterparts a week hence by overcoming Wales in the Galway Sportsground this afternoon, although the latter have given a warning of the challenge they will present by extending an unbeaten English side to an 11-10 win.
London Irish's Courage League match against Northampton, scheduled for Franklin Gardens today, has been postponed due to a water-logged pitch.