England's overseas Test season will go to its 35th day. They have one left to salvage something. New Zealand's summer goes to its final day. They have one left to cling on and secure a precious series victory.
However, it could yet be that the elements play a deciding factor. The clocks have changed and the nights are drawing in. The fourth day was ended early by bad light, the players leaving the field at 4.20pm, and hopes of getting 98 overs on Tuesday appear fanciful given they are not being added to the start of the day due to concerns about dew. Even on Sunday, a brighter day, play finished at around 5.45pm. For the record, New Zealand are 42 for 0 chasing 382.
It highlights the risk of playing Test cricket so late in the New Zealand season, and the fact that it has been pushed to the margins in this country, with the main part of summer given to the pay-billing white-ball formats. These two Tests would have been better the other way round with the floodlit match at Eden Park arranged to coincide with the shorter daylight hours.
Still, if New Zealand are helped by some late gloom they will perhaps think it as evening the scales: last season they were denied an almost-certain series-levelling victory against South Africa in Hamilton when the final day was washed out. If they do come out of Christchurch with a draw - their chances of winning, with what would be the seventh-highest successful chase in Test history, are very slim - it will mean their outstanding performance in Auckland will be rewarded with just a fourth series win over England.
New Zealand haven't been at their best in this match, but have done well to cling to England's coattails having slipped to 36 for 5 in the first innings. Had Jonny Bairstow been given out caught behind on 2 when Marias Erasmus didn't spot an edge off Trent Boult - or had New Zealand not burnt their reviews earlier - the chase may even have been more realistic. England's lead was 311 at the time.
"It would be huge," Craig McMillan, the New Zealand batting coach who played in the 1999 win over England, said of the prospect of taking the series. "We love playing England. The last series we played ended up 1-1. Series wins have been few and far between for New Zealand Test sides. In terms of history it would be very special but there's a big day with lot of cricket ahead so lot of hard work to be done.
"I'm very confident in our position. We've got a tough day ahead, make no bones about that. England are a top side, have quality bowlers and they going to challenge us right through the day. But once guys get in, which at times has been difficult for batsmen, there's opportunities to score runs and bat a long time."
Tom Latham, given a life at slip on 23, and Jeet Raval, who was handed a working over by Stuart Broad and James Anderson, did well to remain unbeaten before the light closed in. The new ball has done less as the match has progressed, but remains challenging, while there were a few signs of grip for left-arm spinner Jack Leach who could yet be a significant factor on his debut.
"It was really impressive. Obviously a tough period against two world-class new-ball bowlers and they had to work hard to get through," McMillan said of the openers. "They got examined in different areas but they did a great job."
England know the conditions will be out of their hands, but remain confident they can create enough chances to level the series even though their second innings did not go entirely to plan. The back-to-back loss of Joe Root and Dawid Malan in the morning then Ben Stokes' departure after lunch meant acceleration was put back a little. Root eventually declared nine down midway through the afternoon session following some belated blows from Bairstow.
"We don't know how long it will be, but there's definitely enough in the pitch for us to take the wickets," Bairstow said. "We've seen if you put the ball in the right areas we've beaten the outside edge consistently, Leachy bowled three overs this evening and some chances were created."
"There's not a massive amount although in the evening session there was a bit of purchase outside the left-hander's off stump,'' he added when speaking to Sky Sports. "He [Leach] needs to learn the right pace because it's obviously slightly different to first-class cricket. I think he's someone who's going to learn very quickly.
"Tomorrow is going to be a massive learning curve for him with the paces, lines and fields he wants to bowl to, but there's no reason why he can't come away with a few wickets.''
England have however long the light allows to try and avoid setting a new record of 13 overseas Tests without a victory. Although, this has been a more encouraging display after hitting the depths of 58 all out in Auckland. There was a lot of talking between matches and the players have lifted significantly.
"The way we came out in this Test was a lot better than we have throughout the winter," Bairstow said. "That's no coincidence after having a couple of chats and I think we are in a decent space as a group to lead into the summer."
One big push for both teams to earn what would be significant results. It could be an absorbing day of Test cricket. Sadly, it could all come to an unsatisfactory end in the dark.
Andrew McGlashan is a deputy editor at ESPNcricinfo