Most often in October, 28 days.
Highest follower count seen that year: 70,754.
January
Jan 3 19:00–24:00 Jan 4 00:00–02:00, 19:00–24:00 Jan 5 00:00–01:00, 19:00–24:00 Jan 6 00:00–01:00 Jan 7 18:00–24:00 Jan 8 00:00–01:00, 19:00–24:00 Jan 9 00:00–01:00 Jan 10 19:00–24:00 Jan 11 00:00–01:00, 18:00–24:00 Jan 12 00:00–01:00, 17:00–21:00 Jan 15 19:00–24:00 Jan 16 00:00–01:00 Jan 17 18:00–23:00 Jan 18 21:00–24:00 Jan 19 00:00–01:00, 18:00–23:00 Jan 21 19:00–24:00 Jan 22 00:00–02:00, 19:00–24:00 Jan 23 00:00–01:00 Jan 25 18:00–24:00 Jan 26 00:00–01:00, 19:00–24:00 Jan 28 19:00–24:00 Jan 29 00:00–02:00, 20:00–24:00 Jan 30 00:00–02:00 Jan 31 18:00–24:00
February
Feb 1 00:00–01:00, 19:00–24:00 Feb 2 00:00–01:00, 14:00–17:00 Feb 4 19:00–24:00 Feb 5 00:00–01:00, 20:00–24:00 Feb 6 00:00–02:00 Feb 7 18:00–24:00 Feb 8 00:00–01:00, 19:00–24:00 Feb 9 00:00–01:00, 15:00–22:00 Feb 12 19:00–24:00 Feb 13 00:00–02:00, 19:00–24:00 Feb 14 00:00–01:00 Feb 16 18:00–24:00 Feb 17 00:00–01:00 Feb 18 19:00–24:00 Feb 19 00:00–01:00, 19:00–24:00 Feb 20 00:00–02:00 Feb 21 19:00–24:00 Feb 22 00:00–02:00, 18:00–24:00 Feb 23 00:00–01:00, 17:00–22:00 Feb 26 18:00–24:00 Feb 27 00:00–01:00, 18:00–24:00 Feb 28 00:00–01:00
March
Mar 1 19:00–24:00 Mar 2 00:00–02:00, 17:00–24:00 Mar 4 19:00–24:00 Mar 5 00:00–01:00, 19:00–24:00 Mar 6 00:00–01:00 Mar 7 19:00–24:00 Mar 8 00:00–02:00, 19:00–24:00 Mar 9 00:00–03:00, 17:00–23:00 Mar 11 20:00–24:00 Mar 12 00:00–02:00 Mar 13 19:00–24:00 Mar 14 00:00–02:00, 19:00–24:00 Mar 15 00:00–03:00, 19:00–24:00 Mar 16 00:00–03:00, 17:00–22:00 Mar 19 19:00–24:00 Mar 20 00:00–02:00 Mar 21 19:00–24:00 Mar 22 00:00–03:00, 20:00–24:00 Mar 23 00:00–03:00, 19:00–24:00 Mar 30 19:00–24:00 Mar 31 00:00–02:00
April
Apr 1 18:00–24:00 Apr 2 00:00–01:00, 19:00–24:00 Apr 3 00:00–02:00, 19:00–24:00 Apr 4 00:00–01:00 Apr 5 19:00–24:00 Apr 6 00:00–01:00, 18:00–23:00 Apr 8 19:00–24:00 Apr 9 00:00–02:00, 21:00–24:00 Apr 10 00:00–02:00, 18:00–21:00 Apr 12 20:00–24:00 Apr 13 00:00–03:00, 19:00–24:00 Apr 15 19:00–24:00 Apr 16 00:00–02:00 Apr 17 20:00–24:00 Apr 18 00:00–02:00, 19:00–24:00 Apr 19 00:00–03:00, 21:00–22:00 Apr 20 17:00–21:00 Apr 22 22:00–24:00 Apr 23 00:00–02:00 Apr 29 17:00–24:00
May
May 3 17:00–23:00 May 4 18:00–24:00 May 7 19:00–24:00 May 8 00:00–02:00, 19:00–24:00 May 9 00:00–01:00, 19:00–24:00 May 10 00:00–02:00, 20:00–24:00 May 11 00:00–03:00, 18:00–22:00 May 16 19:00–24:00 May 17 00:00–02:00, 20:00–24:00 May 18 00:00–03:00, 19:00–24:00 May 19 00:00–03:00 May 20 20:00–24:00 May 21 00:00–02:00, 20:00–24:00 May 22 00:00–02:00, 20:00–24:00 May 23 00:00–03:00 May 25 00:00–03:00, 17:00–24:00 May 27 20:00–24:00 May 28 00:00–03:00, 20:00–24:00 May 29 00:00–03:00 May 31 20:00–24:00
June
Jun 1 00:00–02:00, 19:00–24:00 Jun 2 00:00–02:00 Jun 3 19:00–24:00 Jun 4 00:00–02:00, 16:00–22:00 Jun 6 20:00–24:00 Jun 7 00:00–04:00, 19:00–24:00 Jun 8 00:00–05:00 Jun 9 20:00–24:00 Jun 10 00:00–03:00, 20:00–24:00 Jun 11 00:00–03:00, 18:00–24:00 Jun 12 00:00–01:00 Jun 13 21:00–24:00 Jun 14 00:00–03:00, 19:00–24:00 Jun 15 00:00–05:00, 20:00–24:00 Jun 23 19:00–24:00 Jun 24 00:00–02:00 Jun 25 19:00–24:00 Jun 26 00:00–02:00 Jun 27 19:00–24:00 Jun 28 00:00–02:00, 20:00–24:00 Jun 29 00:00–03:00, 16:00–24:00
July
Jul 1 20:00–24:00 Jul 2 00:00–03:00, 20:00–24:00 Jul 3 00:00–03:00, 20:00–24:00 Jul 4 00:00–03:00, 20:00–24:00 Jul 5 00:00–03:00 Jul 6 18:00–23:00 Jul 9 21:00–24:00 Jul 10 00:00–02:00, 20:00–24:00 Jul 11 00:00–03:00, 21:00–24:00 Jul 12 00:00–03:00 Jul 13 20:00–24:00 Jul 14 00:00–03:00, 20:00–24:00 Jul 15 00:00–04:00 Jul 19 21:00–24:00 Jul 20 00:00–04:00, 20:00–24:00 Jul 21 00:00–03:00 Jul 22 21:00–24:00 Jul 23 00:00–03:00, 21:00–24:00 Jul 24 00:00–02:00 Jul 25 21:00–24:00 Jul 26 00:00–04:00, 21:00–24:00 Jul 27 00:00–05:00, 21:00–24:00 Jul 28 00:00–03:00 Jul 29 21:00–24:00 Jul 30 00:00–01:00
August
Aug 2 18:00–24:00 Aug 3 00:00–03:00, 21:00–24:00 Aug 4 00:00–03:00 Aug 7 21:00–24:00 Aug 8 00:00–03:00, 20:00–24:00 Aug 9 00:00–03:00, 21:00–24:00 Aug 10 00:00–03:00, 18:00–24:00 Aug 11 00:00–02:00 Aug 14 20:00–24:00 Aug 15 00:00–03:00, 23:00–24:00 Aug 16 00:00–04:00, 21:00–24:00 Aug 17 00:00–05:00, 20:00–24:00 Aug 18 00:00–01:00, 20:00–24:00 Aug 19 00:00–02:00 Aug 20 21:00–24:00 Aug 21 00:00–04:00, 21:00–24:00 Aug 22 00:00–04:00, 21:00–24:00 Aug 23 00:00–03:00 Aug 24 19:00–24:00 Aug 25 00:00–01:00 Aug 27 21:00–24:00 Aug 28 00:00–03:00, 21:00–24:00 Aug 29 00:00–03:00 Aug 30 21:00–24:00 Aug 31 00:00–04:00, 21:00–24:00
September
Sep 1 00:00–04:00 Sep 2 21:00–24:00 Sep 3 00:00–04:00, 21:00–24:00 Sep 4 00:00–04:00, 20:00–24:00 Sep 5 00:00–03:00 Sep 6 19:00–24:00 Sep 7 00:00–04:00, 20:00–24:00 Sep 8 00:00–03:00 Sep 10 22:00–24:00 Sep 11 00:00–02:00, 20:00–24:00 Sep 12 00:00–03:00 Sep 14 20:00–24:00 Sep 15 00:00–03:00, 21:00–24:00 Sep 16 00:00–04:00, 21:00–24:00 Sep 17 00:00–03:00 Sep 18 21:00–24:00 Sep 19 00:00–03:00, 21:00–24:00 Sep 20 00:00–04:00, 21:00–24:00 Sep 21 00:00–03:00, 22:00–24:00 Sep 22 00:00–02:00 Sep 24 21:00–24:00 Sep 25 00:00–03:00 Sep 26 21:00–24:00 Sep 27 00:00–03:00, 21:00–24:00 Sep 28 00:00–04:00 Sep 30 21:00–24:00
October
Oct 1 00:00–04:00, 21:00–24:00 Oct 2 00:00–03:00, 20:00–24:00 Oct 3 00:00–01:00 Oct 4 21:00–24:00 Oct 5 00:00–03:00, 21:00–24:00 Oct 6 00:00–04:00 Oct 7 21:00–24:00 Oct 8 00:00–04:00, 21:00–24:00 Oct 9 00:00–04:00 Oct 10 22:00–24:00 Oct 11 00:00–05:00, 21:00–24:00 Oct 12 00:00–04:00, 21:00–24:00 Oct 13 00:00–04:00 Oct 16 22:00–24:00 Oct 17 00:00–04:00, 22:00–24:00 Oct 18 00:00–04:00 Oct 20 23:00–24:00 Oct 21 00:00–04:00, 21:00–24:00 Oct 22 00:00–03:00 Oct 23 23:00–24:00 Oct 24 00:00–03:00 Oct 25 19:00–24:00 Oct 26 00:00–03:00, 19:00–24:00 Oct 27 00:00–02:00 Oct 28 21:00–24:00 Oct 29 00:00–04:00, 21:00–24:00 Oct 30 00:00–02:00, 21:00–24:00 Oct 31 00:00–04:00, 20:00–24:00
November
Nov 1 00:00–04:00, 20:00–24:00 Nov 2 00:00–03:00, 20:00–24:00 Nov 3 00:00–01:00 Nov 21 19:00–24:00 Nov 22 00:00–01:00, 21:00–24:00 Nov 23 00:00–02:00, 20:00–24:00 Nov 24 00:00–02:00, 20:00–24:00 Nov 25 00:00–02:00, 21:00–24:00 Nov 26 00:00–03:00 Nov 27 20:00–24:00 Nov 28 00:00–03:00, 22:00–24:00 Nov 29 00:00–04:00, 21:00–24:00 Nov 30 00:00–04:00, 21:00–24:00
December
Dec 1 00:00–02:00 Dec 3 22:00–24:00 Dec 4 00:00–03:00, 20:00–24:00 Dec 5 00:00–03:00, 19:00–24:00 Dec 6 00:00–03:00, 21:00–24:00 Dec 7 00:00–04:00, 20:00–24:00 Dec 8 00:00–02:00, 20:00–24:00 Dec 9 00:00–02:00, 22:00–24:00 Dec 10 00:00–02:00 Dec 12 21:00–24:00 Dec 13 00:00–04:00, 20:00–24:00 Dec 14 00:00–02:00, 20:00–24:00 Dec 15 00:00–03:00, 21:00–24:00 Dec 16 00:00–02:00, 22:00–24:00 Dec 17 00:00–02:00 Dec 21 20:00–24:00 Dec 22 00:00–03:00, 21:00–24:00 Dec 23 00:00–03:00, 21:00–24:00 Dec 24 00:00–03:00, 20:00–24:00 Dec 25 00:00–03:00, 21:00–24:00 Dec 26 00:00–02:00 Dec 27 20:00–24:00 Dec 28 00:00–03:00, 21:00–24:00 Dec 29 00:00–02:00 Dec 30 20:00–24:00 Dec 31 00:00–02:00