Most often in November, 29 days.
Highest follower count seen that year: 67,695.
January
Jan 10 21:00–24:00 Jan 11 02:00–04:00, 16:00–24:00 Jan 12 17:00–24:00 Jan 13 17:00–24:00 Jan 14 17:00–24:00 Jan 16 16:00–23:00 Jan 18 15:00–22:00 Jan 19 17:00–24:00 Jan 21 17:00–24:00 Jan 22 17:00–24:00 Jan 24 17:00–24:00 Jan 25 18:00–24:00 Jan 26 00:00–01:00, 19:00–24:00 Jan 27 00:00–02:00 Jan 28 18:00–24:00 Jan 29 00:00–01:00, 18:00–24:00 Jan 30 00:00–01:00 Jan 31 19:00–24:00
February
Feb 1 17:00–24:00 Feb 2 18:00–24:00 Feb 4 18:00–24:00 Feb 5 00:00–01:00, 18:00–24:00 Feb 6 00:00–01:00 Feb 7 17:00–24:00 Feb 8 18:00–19:00 Feb 9 17:00–24:00 Feb 10 16:00–23:00 Feb 13 15:00–22:00 Feb 14 16:00–23:00 Feb 15 18:00–24:00 Feb 16 00:00–01:00, 18:00–24:00 Feb 19 17:00–24:00 Feb 20 17:00–23:00 Feb 21 18:00–24:00 Feb 22 00:00–01:00 Feb 23 05:00–11:00, 17:00–20:00 Feb 25 12:00–19:00 Feb 26 16:00–22:00 Feb 28 18:00–24:00
March
Mar 1 00:00–01:00, 18:00–24:00 Mar 2 00:00–01:00, 17:00–23:00 Mar 4 18:00–24:00 Mar 5 00:00–01:00, 18:00–24:00 Mar 7 21:00–24:00 Mar 8 00:00–03:00, 20:00–24:00 Mar 9 00:00–02:00, 20:00–24:00 Mar 10 00:00–02:00 Mar 12 19:00–24:00 Mar 13 00:00–01:00, 21:00–24:00 Mar 14 00:00–03:00, 21:00–24:00 Mar 15 00:00–04:00 Mar 16 22:00–24:00 Mar 17 00:00–04:00 Mar 18 01:00–08:00 Mar 20 22:00–24:00 Mar 21 00:00–04:00 Mar 22 00:00–06:00 Mar 23 00:00–06:00, 17:00–23:00 Mar 27 17:00–23:00 Mar 28 17:00–23:00 Mar 29 17:00–23:00 Mar 30 17:00–23:00
April
Apr 2 18:00–24:00 Apr 3 00:00–01:00, 20:00–24:00 Apr 4 17:00–23:00 Apr 5 17:00–23:00 Apr 6 18:00–24:00 Apr 8 19:00–24:00 Apr 9 00:00–01:00 Apr 10 20:00–24:00 Apr 11 00:00–02:00 Apr 12 18:00–24:00 Apr 14 17:00–23:00 Apr 15 18:00–24:00 Apr 17 16:00–22:00 Apr 19 22:00–23:00 Apr 21 00:00–07:00 Apr 23 18:00–24:00 Apr 24 19:00–24:00 Apr 25 00:00–01:00, 18:00–24:00 Apr 27 21:00–24:00 Apr 28 00:00–02:00 Apr 29 17:00–23:00
May
May 1 17:00–22:00 May 2 16:00–22:00 May 3 21:00–24:00 May 4 00:00–02:00, 18:00–24:00 May 5 00:00–01:00 May 7 18:00–23:00 May 9 18:00–24:00 May 10 00:00–01:00, 18:00–24:00 May 11 00:00–01:00, 19:00–24:00 May 12 01:00–03:00 May 15 20:00–24:00 May 16 00:00–02:00, 19:00–24:00 May 17 19:00–24:00 May 18 00:00–02:00, 20:00–24:00 May 19 00:00–03:00 May 21 18:00–24:00 May 22 19:00–24:00 May 23 00:00–01:00, 19:00–20:00 May 24 19:00–24:00 May 25 00:00–02:00, 19:00–24:00 May 26 00:00–02:00 May 28 19:00–24:00 May 29 00:00–01:00, 17:00–23:00 May 30 20:00–24:00 May 31 00:00–01:00, 18:00–24:00
June
Jun 1 00:00–01:00, 18:00–24:00 Jun 2 00:00–01:00 Jun 4 15:00–22:00 Jun 6 19:00–24:00 Jun 7 00:00–02:00 Jun 8 17:00–24:00 Jun 11 19:00–24:00 Jun 12 00:00–01:00, 23:00–24:00 Jun 13 00:00–05:00, 20:00–23:00 Jun 14 20:00–24:00 Jun 15 00:00–02:00, 22:00–24:00 Jun 16 00:00–05:00 Jun 18 21:00–24:00 Jun 19 00:00–03:00, 21:00–24:00 Jun 20 00:00–03:00 Jun 21 20:00–24:00 Jun 22 00:00–01:00, 23:00–24:00 Jun 23 00:00–05:00 Jun 25 20:00–24:00 Jun 26 00:00–02:00, 23:00–24:00 Jun 27 00:00–05:00 Jun 28 20:00–24:00 Jun 29 00:00–03:00, 17:00–24:00
July
Jul 2 20:00–24:00 Jul 3 00:00–03:00, 21:00–24:00 Jul 4 00:00–01:00, 21:00–24:00 Jul 5 00:00–03:00, 21:00–24:00 Jul 6 00:00–04:00, 22:00–24:00 Jul 7 00:00–05:00 Jul 9 20:00–24:00 Jul 10 00:00–02:00, 15:00–21:00 Jul 11 21:00–24:00 Jul 12 00:00–03:00, 22:00–24:00 Jul 13 00:00–03:00, 21:00–24:00 Jul 14 00:00–03:00 Jul 16 23:00–24:00 Jul 17 00:00–06:00, 22:00–24:00 Jul 18 00:00–01:00, 23:00–24:00 Jul 19 00:00–04:00, 22:00–24:00 Jul 20 00:00–05:00, 22:00–24:00 Jul 21 00:00–03:00, 23:00–24:00 Jul 22 00:00–05:00 Jul 23 22:00–24:00 Jul 24 00:00–05:00 Jul 25 21:00–24:00 Jul 26 00:00–03:00, 23:00–24:00 Jul 27 00:00–05:00, 23:00–24:00 Jul 28 00:00–05:00 Jul 29 21:00–24:00 Jul 30 00:00–03:00, 23:00–24:00
August
Aug 1 20:00–24:00 Aug 2 00:00–04:00 Aug 3 00:00–05:00, 21:00–24:00 Aug 4 00:00–03:00 Aug 6 22:00–24:00 Aug 7 00:00–05:00 Aug 8 00:00–05:00, 16:00–18:00, 23:00–24:00 Aug 9 00:00–05:00 Aug 10 00:00–05:00, 23:00–24:00 Aug 11 00:00–06:00 Aug 12 21:00–24:00 Aug 13 00:00–04:00, 22:00–24:00 Aug 14 00:00–03:00 Aug 15 21:00–24:00 Aug 16 00:00–03:00 Aug 17 21:00–24:00 Aug 18 00:00–03:00 Aug 20 23:00–24:00 Aug 21 00:00–04:00, 23:00–24:00 Aug 22 00:00–05:00, 23:00–24:00 Aug 23 00:00–05:00 Aug 24 00:00–05:00 Aug 26 18:00–24:00 Aug 27 00:00–01:00, 20:00–24:00 Aug 28 00:00–02:00, 21:00–24:00 Aug 29 00:00–03:00 Aug 30 17:00–24:00 Aug 31 18:00–23:00
September
Sep 3 18:00–24:00 Sep 5 07:00–13:00, 21:00–24:00 Sep 6 00:00–02:00, 20:00–24:00 Sep 7 00:00–02:00, 22:00–24:00 Sep 8 00:00–04:00, 20:00–24:00 Sep 9 00:00–01:00, 22:00–24:00 Sep 10 00:00–04:00, 23:00–24:00 Sep 11 00:00–05:00 Sep 12 23:00–24:00 Sep 13 00:00–03:00 Sep 14 20:00–24:00 Sep 15 00:00–01:00 Sep 17 22:00–24:00 Sep 18 00:00–03:00, 23:00–24:00 Sep 19 00:00–03:00, 22:00–24:00 Sep 20 00:00–02:00, 22:00–24:00 Sep 21 00:00–01:00 Sep 24 20:00–24:00 Sep 25 00:00–02:00, 21:00–24:00 Sep 26 00:00–03:00, 18:00–24:00 Sep 27 21:00–24:00 Sep 28 00:00–03:00, 23:00–24:00 Sep 29 00:00–01:00, 21:00–24:00 Sep 30 00:00–03:00, 19:00–24:00
October
Oct 1 00:00–02:00, 21:00–24:00 Oct 2 00:00–04:00 Oct 4 20:00–24:00 Oct 5 00:00–03:00, 16:00–24:00 Oct 6 18:00–24:00 Oct 7 00:00–01:00, 19:00–24:00 Oct 8 00:00–01:00, 18:00–24:00 Oct 9 00:00–01:00 Oct 13 18:00–24:00 Oct 15 18:00–24:00 Oct 16 00:00–01:00, 20:00–24:00 Oct 17 00:00–01:00, 20:00–24:00 Oct 18 00:00–01:00, 19:00–24:00 Oct 19 00:00–02:00, 19:00–24:00 Oct 22 17:00–23:00 Oct 23 18:00–23:00 Oct 24 20:00–24:00 Oct 25 00:00–01:00, 18:00–24:00 Oct 26 00:00–01:00 Oct 28 20:00–24:00 Oct 29 00:00–01:00, 20:00–24:00 Oct 30 00:00–02:00, 20:00–24:00 Oct 31 00:00–02:00, 21:00–24:00
November
Nov 1 17:00–24:00 Nov 2 19:00–24:00 Nov 3 00:00–01:00 Nov 4 19:00–24:00 Nov 5 00:00–02:00 Nov 6 19:00–24:00 Nov 7 00:00–01:00 Nov 8 20:00–24:00 Nov 9 00:00–02:00, 20:00–24:00 Nov 10 00:00–02:00, 21:00–24:00 Nov 11 00:00–01:00 Nov 12 20:00–24:00 Nov 13 00:00–03:00 Nov 14 19:00–23:00 Nov 15 20:00–24:00 Nov 16 00:00–02:00, 19:00–24:00 Nov 17 00:00–01:00 Nov 18 19:00–24:00 Nov 19 00:00–01:00, 21:00–24:00 Nov 20 00:00–02:00 Nov 21 20:00–24:00 Nov 22 00:00–01:00, 21:00–24:00 Nov 23 00:00–03:00, 21:00–24:00 Nov 24 00:00–01:00 Nov 25 18:00–24:00 Nov 26 00:00–01:00 Nov 28 20:00–24:00 Nov 29 00:00–02:00, 19:00–24:00 Nov 30 00:00–01:00, 20:00–24:00
December
Dec 1 00:00–02:00 Dec 2 18:00–24:00 Dec 3 21:00–24:00 Dec 4 20:00–24:00 Dec 5 00:00–01:00 Dec 6 20:00–24:00 Dec 7 00:00–01:00 Dec 8 01:00–07:00 Dec 10 17:00–24:00 Dec 11 17:00–23:00 Dec 12 19:00–24:00 Dec 13 00:00–01:00 Dec 14 19:00–24:00 Dec 16 18:00–24:00 Dec 17 00:00–01:00, 18:00–24:00 Dec 18 09:00–13:00 Dec 20 21:00–24:00 Dec 21 00:00–02:00, 19:00–24:00 Dec 24 16:00–23:00 Dec 25 19:00–22:00 Dec 28 18:00–19:00, 23:00–24:00 Dec 29 00:00–05:00, 19:00–24:00 Dec 31 06:00–11:00