310.
Does not matter.
Even if Djokovic loses in the first round, he will retain his 2000 champion points.
(Not only him, any player will keep the same number of points as Australia 2020 unless he exceeds it in 2021, which in the case of the Serbian is obviously not possible).
The ATP already decided so a few weeks ago
So, what Djokovic and Nadal do in London will determine whether Nole will beat Federer's record in the second week of March 2021 or on the contrary, Bull can cut the number of points and if he does, he would have a small chance of being the one again. 1 in the ranking when the Australian Open ends, since the Spanish will have the possibility of adding points since they only managed to reach the quarterfinals in the 2020 edition (360 points).
Anyway, be it in March or later, it seems to be inevitable that Joker will surpass the 310-week record as world number 1 still held by Federer.