Most often in November, 24 days.
Highest follower count seen that year: 19,877.
January
Jan 2 01:00–07:00, 19:00–22:00 Jan 3 00:00–07:00 Jan 4 02:00–07:00 Jan 9 02:00–07:00 Jan 10 21:00–24:00 Jan 11 03:00–07:00 Jan 14 07:00–09:00 Jan 15 03:00–07:00, 21:00–24:00 Jan 16 00:00–07:00 Jan 18 04:00–05:00 Jan 23 03:00–08:00 Jan 24 04:00–07:00 Jan 28 04:00–06:00 Jan 29 01:00–05:00 Jan 30 03:00–05:00 Jan 31 03:00–07:00, 19:00–24:00
February
Feb 1 00:00–01:00, 03:00–07:00 Feb 3 03:00–06:00 Feb 6 01:00–06:00 Feb 7 01:00–05:00, 20:00–23:00 Feb 17 19:00–24:00 Feb 18 00:00–06:00, 20:00–23:00 Feb 19 00:00–06:00 Feb 20 01:00–06:00, 23:00–24:00 Feb 21 00:00–07:00 Feb 22 03:00–07:00, 23:00–24:00 Feb 23 00:00–08:00 Feb 24 19:00–21:00 Feb 26 04:00–07:00 Feb 27 23:00–24:00 Feb 28 00:00–06:00
March
Mar 4 05:00–07:00, 20:00–24:00 Mar 5 00:00–06:00, 23:00–24:00 Mar 6 00:00–07:00, 22:00–24:00 Mar 7 00:00–06:00, 17:00–19:00 Mar 15 00:00–06:00 Mar 17 04:00–07:00, 19:00–23:00 Mar 18 03:00–08:00 Mar 19 00:00–07:00 Mar 21 02:00–08:00 Mar 24 21:00–23:00 Mar 25 21:00–24:00 Mar 31 18:00–23:00
April
Apr 1 18:00–21:00 Apr 2 03:00–05:00 Apr 4 02:00–05:00 Apr 5 00:00–07:00 Apr 7 18:00–23:00 Apr 8 00:00–06:00, 20:00–24:00 Apr 9 00:00–01:00, 03:00–06:00 Apr 14 03:00–06:00, 22:00–24:00 Apr 15 00:00–04:00, 22:00–24:00 Apr 16 00:00–03:00, 20:00–24:00 Apr 19 02:00–06:00 Apr 22 21:00–24:00 Apr 23 03:00–07:00, 23:00–24:00 Apr 24 00:00–07:00, 20:00–24:00 Apr 25 01:00–07:00 Apr 26 03:00–08:00 Apr 28 05:00–07:00 Apr 29 00:00–01:00 Apr 30 06:00–09:00
May
May 2 07:00–08:00 May 4 04:00–08:00 May 6 20:00–24:00 May 7 00:00–01:00, 04:00–05:00, 19:00–22:00 May 8 04:00–09:00 May 9 04:00–06:00 May 18 22:00–24:00 May 19 00:00–05:00, 20:00–24:00 May 20 00:00–01:00 May 21 18:00–24:00 May 22 00:00–06:00, 18:00–24:00 May 23 00:00–06:00, 18:00–21:00 May 24 04:00–09:00 May 26 03:00–05:00 May 28 00:00–06:00 May 29 18:00–21:00 May 31 03:00–06:00
June
Jun 1 21:00–24:00 Jun 2 00:00–01:00, 04:00–05:00, 18:00–22:00 Jun 3 02:00–06:00 Jun 4 03:00–07:00 Jun 7 05:00–08:00 Jun 21 01:00–06:00 Jun 24 05:00–06:00 Jun 25 02:00–07:00, 23:00–24:00 Jun 26 00:00–03:00 Jun 27 02:00–06:00
July
Jul 1 19:00–23:00 Jul 3 18:00–20:00 Jul 4 23:00–24:00 Jul 5 00:00–05:00 Jul 11 03:00–05:00 Jul 12 04:00–07:00 Jul 14 03:00–06:00, 18:00–21:00 Jul 15 01:00–06:00, 23:00–24:00 Jul 16 00:00–02:00, 05:00–07:00, 21:00–24:00 Jul 17 03:00–08:00 Jul 18 04:00–07:00 Jul 19 02:00–06:00 Jul 20 22:00–24:00 Jul 21 03:00–06:00, 22:00–24:00 Jul 22 02:00–05:00 Jul 23 00:00–05:00, 22:00–24:00 Jul 24 03:00–05:00 Jul 25 03:00–06:00, 23:00–24:00 Jul 26 00:00–05:00 Jul 27 22:00–24:00 Jul 28 00:00–05:00, 21:00–24:00 Jul 29 00:00–05:00, 23:00–24:00 Jul 30 00:00–04:00, 22:00–24:00 Jul 31 00:00–05:00
August
Aug 11 17:00–24:00 Aug 12 01:00–04:00 Aug 13 03:00–05:00 Aug 14 00:00–03:00 Aug 15 03:00–04:00, 22:00–24:00 Aug 16 00:00–06:00 Aug 20 03:00–05:00 Aug 21 21:00–23:00 Aug 22 19:00–22:00 Aug 23 01:00–03:00 Aug 24 21:00–24:00 Aug 25 00:00–01:00 Aug 26 00:00–05:00 Aug 28 02:00–05:00 Aug 30 04:00–06:00
September
Sep 6 22:00–24:00 Sep 7 02:00–06:00 Sep 8 19:00–24:00 Sep 9 00:00–04:00 Sep 10 01:00–02:00, 04:00–06:00 Sep 14 01:00–05:00, 19:00–21:00 Sep 15 03:00–06:00 Sep 17 20:00–21:00 Sep 23 04:00–08:00
October
Oct 12 15:00–16:00 Oct 17 05:00–07:00 Oct 18 00:00–05:00 Oct 21 01:00–05:00, 19:00–24:00 Oct 22 00:00–01:00, 03:00–06:00, 21:00–24:00 Oct 23 03:00–05:00, 20:00–22:00 Oct 24 18:00–21:00 Oct 25 03:00–05:00 Oct 27 19:00–22:00 Oct 29 20:00–24:00 Oct 30 05:00–07:00 Oct 31 03:00–06:00
November
Nov 1 02:00–08:00, 19:00–24:00 Nov 2 04:00–09:00, 18:00–20:00 Nov 4 03:00–05:00, 18:00–19:00 Nov 9 22:00–24:00 Nov 10 00:00–07:00, 20:00–23:00 Nov 11 00:00–05:00, 23:00–24:00 Nov 12 00:00–01:00, 05:00–08:00, 19:00–20:00 Nov 13 01:00–08:00, 22:00–24:00 Nov 14 02:00–05:00, 17:00–19:00, 22:00–24:00 Nov 15 00:00–02:00, 05:00–09:00, 23:00–24:00 Nov 16 00:00–01:00, 03:00–05:00 Nov 17 22:00–23:00 Nov 18 01:00–07:00, 21:00–24:00 Nov 19 00:00–02:00, 05:00–07:00, 23:00–24:00 Nov 20 00:00–01:00, 03:00–07:00, 23:00–24:00 Nov 21 00:00–07:00, 22:00–24:00 Nov 22 00:00–06:00 Nov 23 05:00–07:00, 21:00–24:00 Nov 24 00:00–03:00 Nov 25 04:00–07:00, 23:00–24:00 Nov 26 00:00–05:00 Nov 27 00:00–07:00 Nov 28 04:00–09:00 Nov 30 23:00–24:00
December
Dec 1 00:00–05:00, 07:00–08:00 Dec 2 23:00–24:00 Dec 3 00:00–06:00 Dec 7 20:00–22:00 Dec 15 18:00–21:00 Dec 17 23:00–24:00 Dec 18 00:00–05:00 Dec 19 23:00–24:00 Dec 20 23:00–24:00 Dec 21 00:00–05:00 Dec 23 02:00–07:00