Most often in November, 25 days.
Highest follower count seen that year: 20,244.
January
Jan 1 23:00–24:00 Jan 2 00:00–07:00 Jan 3 20:00–24:00 Jan 4 00:00–06:00 Jan 5 23:00–24:00 Jan 6 00:00–04:00 Jan 16 19:00–24:00 Jan 17 00:00–01:00, 20:00–24:00 Jan 18 00:00–02:00 Jan 19 22:00–24:00 Jan 20 00:00–05:00 Jan 24 02:00–04:00, 22:00–23:00 Jan 25 23:00–24:00 Jan 26 00:00–04:00 Jan 27 01:00–04:00 Jan 31 22:00–24:00
February
Feb 1 00:00–03:00, 23:00–24:00 Feb 2 00:00–04:00, 19:00–24:00 Feb 3 00:00–04:00 Feb 5 01:00–06:00, 23:00–24:00 Feb 6 00:00–06:00, 22:00–24:00 Feb 7 00:00–04:00 Feb 8 01:00–03:00, 23:00–24:00 Feb 9 00:00–06:00, 23:00–24:00 Feb 10 00:00–04:00 Feb 13 02:00–09:00 Feb 14 01:00–07:00 Feb 17 02:00–12:00 Feb 19 04:00–11:00 Feb 20 04:00–07:00 Feb 28 09:00–24:00
March
Mar 1 00:00–02:00, 19:00–24:00 Mar 2 00:00–02:00, 14:00–22:00 Mar 3 02:00–03:00 Mar 4 20:00–24:00 Mar 6 13:00–14:00, 21:00–24:00 Mar 8 01:00–04:00, 19:00–24:00 Mar 9 00:00–03:00 Mar 10 00:00–02:00 Mar 13 21:00–24:00 Mar 14 00:00–01:00, 22:00–24:00 Mar 15 01:00–04:00, 23:00–24:00 Mar 16 00:00–04:00, 22:00–24:00 Mar 17 00:00–05:00 Mar 19 02:00–06:00 Mar 20 04:00–07:00, 21:00–24:00 Mar 21 00:00–07:00, 22:00–24:00 Mar 22 00:00–04:00 Mar 23 01:00–12:00, 23:00–24:00 Mar 24 00:00–05:00 Mar 29 03:00–18:00, 20:00–23:00
April
Apr 2 11:00–15:00, 17:00–21:00 Apr 3 12:00–19:00 Apr 6 11:00–15:00, 21:00–22:00 Apr 7 00:00–01:00 Apr 9 15:00–16:00 Apr 13 18:00–24:00 Apr 14 00:00–03:00 Apr 18 01:00–07:00, 13:00–24:00 Apr 20 22:00–24:00 Apr 21 00:00–03:00 Apr 22 17:00–24:00 Apr 23 00:00–02:00, 20:00–24:00 Apr 24 00:00–04:00 Apr 25 20:00–23:00 Apr 26 20:00–24:00 Apr 27 00:00–03:00, 15:00–17:00, 21:00–24:00 Apr 28 00:00–01:00
May
May 1 00:00–05:00, 23:00–24:00 May 2 00:00–03:00, 23:00–24:00 May 3 00:00–04:00, 20:00–23:00 May 7 18:00–24:00 May 8 01:00–02:00, 23:00–24:00 May 9 00:00–05:00 May 10 21:00–24:00 May 11 00:00–01:00, 19:00–23:00 May 13 23:00–24:00 May 14 00:00–09:00 May 15 00:00–03:00, 15:00–16:00, 18:00–23:00 May 16 22:00–24:00 May 17 00:00–08:00, 23:00–24:00 May 18 00:00–03:00 May 19 02:00–07:00 May 22 03:00–10:00 May 23 02:00–07:00, 23:00–24:00 May 24 00:00–06:00 May 25 02:00–04:00, 08:00–12:00 May 27 22:00–24:00 May 28 00:00–10:00 May 29 02:00–14:00 May 30 03:00–09:00 May 31 01:00–09:00, 20:00–24:00
June
Jun 1 00:00–01:00, 05:00–08:00, 21:00–24:00 Jun 2 00:00–02:00, 04:00–05:00 Jun 5 02:00–06:00, 12:00–18:00 Jun 6 04:00–07:00 Jun 7 08:00–19:00 Jun 17 14:00–18:00 Jun 18 09:00–17:00 Jun 22 16:00–21:00 Jun 29 02:00–05:00
July
Jul 1 13:00–17:00 Jul 2 16:00–17:00 Jul 4 12:00–17:00 Jul 6 00:00–05:00, 13:00–15:00 Jul 9 08:00–16:00 Jul 10 13:00–17:00 Jul 11 06:00–17:00 Jul 12 11:00–17:00, 20:00–23:00 Jul 16 03:00–07:00, 10:00–15:00, 20:00–23:00 Jul 17 11:00–14:00 Jul 19 02:00–07:00 Jul 20 09:00–21:00 Jul 25 04:00–08:00, 12:00–17:00 Jul 26 00:00–01:00 Jul 27 21:00–24:00 Jul 29 17:00–18:00, 20:00–23:00 Jul 31 13:00–22:00
August
Aug 1 10:00–16:00 Aug 2 18:00–21:00 Aug 3 12:00–15:00, 20:00–21:00 Aug 4 19:00–24:00 Aug 9 19:00–23:00 Aug 10 13:00–16:00, 18:00–23:00 Aug 13 00:00–05:00, 22:00–24:00 Aug 14 00:00–01:00 Aug 15 22:00–24:00 Aug 16 00:00–03:00 Aug 17 02:00–07:00, 16:00–24:00 Aug 18 00:00–01:00 Aug 22 22:00–24:00 Aug 23 00:00–02:00, 22:00–24:00 Aug 24 00:00–01:00, 21:00–24:00 Aug 26 22:00–24:00 Aug 27 00:00–06:00, 18:00–24:00 Aug 28 00:00–02:00, 21:00–24:00 Aug 29 00:00–01:00, 21:00–24:00 Aug 30 00:00–02:00, 21:00–24:00 Aug 31 00:00–06:00, 16:00–24:00
September
Sep 1 00:00–04:00 Sep 3 21:00–24:00 Sep 4 00:00–02:00, 23:00–24:00 Sep 5 00:00–03:00, 22:00–24:00 Sep 7 19:00–24:00 Sep 8 00:00–02:00 Sep 10 23:00–24:00 Sep 11 00:00–06:00, 17:00–24:00 Sep 12 18:00–24:00 Sep 13 23:00–24:00 Sep 14 00:00–03:00, 22:00–24:00 Sep 15 00:00–04:00 Sep 17 23:00–24:00 Sep 18 00:00–02:00, 14:00–17:00 Sep 27 02:00–06:00 Sep 28 14:00–24:00 Sep 29 00:00–02:00
October
Oct 1 13:00–15:00 Oct 3 18:00–24:00 Oct 4 00:00–02:00, 13:00–19:00 Oct 5 20:00–24:00 Oct 6 00:00–01:00 Oct 11 14:00–22:00 Oct 12 14:00–24:00 Oct 13 00:00–02:00 Oct 14 03:00–06:00 Oct 15 23:00–24:00 Oct 16 00:00–03:00, 15:00–21:00 Oct 17 22:00–24:00 Oct 18 00:00–01:00 Oct 19 18:00–24:00 Oct 20 00:00–01:00 Oct 22 04:00–10:00, 23:00–24:00 Oct 23 00:00–01:00 Oct 24 21:00–24:00 Oct 25 16:00–19:00, 23:00–24:00 Oct 26 00:00–02:00, 14:00–23:00 Oct 27 00:00–02:00 Oct 29 01:00–04:00 Oct 30 03:00–06:00, 22:00–24:00 Oct 31 00:00–02:00, 22:00–24:00
November
Nov 1 00:00–02:00 Nov 2 03:00–06:00, 21:00–24:00 Nov 3 00:00–03:00 Nov 5 01:00–07:00, 20:00–24:00 Nov 6 23:00–24:00 Nov 7 00:00–01:00 Nov 8 03:00–06:00 Nov 9 01:00–04:00, 20:00–24:00 Nov 10 00:00–02:00 Nov 13 19:00–24:00 Nov 14 00:00–01:00, 22:00–24:00 Nov 15 00:00–02:00, 20:00–24:00 Nov 16 00:00–02:00, 19:00–24:00 Nov 17 00:00–04:00 Nov 20 03:00–07:00 Nov 21 00:00–03:00 Nov 22 03:00–07:00 Nov 23 20:00–24:00 Nov 24 00:00–06:00 Nov 25 04:00–07:00 Nov 26 01:00–04:00 Nov 27 03:00–10:00, 23:00–24:00 Nov 28 00:00–05:00 Nov 29 01:00–03:00 Nov 30 01:00–04:00, 23:00–24:00
December
Dec 1 01:00–09:00 Dec 3 03:00–08:00 Dec 5 02:00–07:00 Dec 7 03:00–07:00, 20:00–24:00 Dec 8 00:00–03:00 Dec 10 02:00–07:00 Dec 11 02:00–10:00, 19:00–22:00 Dec 12 03:00–07:00, 13:00–17:00 Dec 13 05:00–10:00 Dec 14 03:00–08:00, 23:00–24:00 Dec 15 00:00–02:00, 04:00–07:00 Dec 18 05:00–12:00, 14:00–16:00 Dec 19 05:00–06:00, 08:00–13:00 Dec 21 17:00–22:00 Dec 22 05:00–10:00 Dec 27 05:00–06:00, 08:00–09:00 Dec 29 09:00–15:00