Most often in October, 28 days.
Highest follower count seen that year: 13,743.
January
Jan 2 23:00–24:00 Jan 3 00:00–02:00, 16:00–19:00 Jan 4 17:00–19:00 Jan 5 02:00–04:00, 22:00–24:00 Jan 6 22:00–24:00 Jan 7 23:00–24:00 Jan 8 00:00–02:00, 21:00–24:00 Jan 9 22:00–24:00 Jan 11 05:00–07:00 Jan 16 01:00–06:00 Jan 17 04:00–05:00, 07:00–09:00 Jan 18 04:00–12:00 Jan 19 07:00–11:00 Jan 20 03:00–06:00, 23:00–24:00 Jan 21 00:00–02:00, 04:00–05:00, 07:00–09:00 Jan 22 01:00–04:00 Jan 24 04:00–06:00, 23:00–24:00 Jan 25 00:00–03:00 Jan 26 07:00–08:00 Jan 27 21:00–24:00 Jan 30 05:00–06:00, 08:00–10:00 Jan 31 04:00–06:00
February
Feb 10 23:00–24:00 Feb 11 04:00–06:00, 23:00–24:00 Feb 12 07:00–08:00 Feb 14 22:00–24:00 Feb 15 00:00–01:00, 05:00–06:00 Feb 16 06:00–08:00, 20:00–22:00 Feb 17 04:00–09:00 Feb 18 19:00–22:00 Feb 20 23:00–24:00 Feb 21 00:00–01:00, 21:00–23:00 Feb 22 23:00–24:00 Feb 23 00:00–02:00 Feb 24 05:00–07:00 Feb 26 19:00–20:00 Feb 27 00:00–01:00, 21:00–22:00
March
Mar 1 22:00–23:00 Mar 2 00:00–01:00 Mar 3 04:00–08:00, 23:00–24:00 Mar 7 21:00–24:00 Mar 9 20:00–23:00 Mar 11 17:00–19:00, 21:00–24:00 Mar 12 23:00–24:00 Mar 13 03:00–04:00 Mar 14 04:00–05:00, 20:00–22:00 Mar 16 00:00–01:00 Mar 17 21:00–22:00 Mar 18 22:00–24:00 Mar 20 20:00–22:00 Mar 21 20:00–23:00 Mar 23 00:00–02:00 Mar 24 16:00–20:00, 23:00–24:00 Mar 26 20:00–22:00 Mar 27 02:00–05:00
April
Apr 1 18:00–21:00 Apr 3 20:00–23:00 Apr 4 17:00–20:00 Apr 5 04:00–07:00, 17:00–21:00 Apr 6 05:00–06:00 Apr 8 07:00–09:00, 21:00–24:00 Apr 9 00:00–01:00 Apr 10 04:00–09:00, 21:00–24:00 Apr 12 04:00–06:00, 20:00–24:00 Apr 13 03:00–06:00 Apr 14 23:00–24:00 Apr 15 00:00–02:00, 04:00–06:00 Apr 19 06:00–09:00 Apr 21 04:00–05:00 Apr 30 02:00–03:00, 06:00–10:00
May
May 2 05:00–06:00, 08:00–10:00 May 3 04:00–09:00 May 4 07:00–09:00 May 5 06:00–12:00 May 6 05:00–11:00 May 8 05:00–07:00 May 15 04:00–05:00, 08:00–10:00 May 20 19:00–22:00 May 21 06:00–09:00 May 22 21:00–23:00 May 24 06:00–07:00 May 27 03:00–06:00, 23:00–24:00 May 28 00:00–02:00 May 29 00:00–01:00
June
Jun 1 00:00–02:00, 07:00–08:00 Jun 2 06:00–07:00, 22:00–24:00 Jun 3 00:00–02:00 Jun 4 05:00–06:00 Jun 5 02:00–04:00 Jun 6 05:00–07:00, 20:00–22:00 Jun 7 08:00–10:00 Jun 8 07:00–10:00 Jun 9 03:00–05:00, 20:00–22:00 Jun 10 01:00–03:00, 06:00–07:00 Jun 14 22:00–24:00 Jun 15 00:00–01:00, 21:00–24:00 Jun 17 01:00–03:00, 23:00–24:00 Jun 18 00:00–01:00 Jun 19 04:00–05:00, 21:00–22:00 Jun 20 06:00–08:00 Jun 21 06:00–08:00, 11:00–12:00 Jun 22 21:00–23:00 Jun 23 20:00–24:00 Jun 24 21:00–22:00 Jun 25 05:00–06:00 Jun 26 03:00–05:00 Jun 28 05:00–07:00 Jun 29 22:00–24:00 Jun 30 00:00–01:00, 18:00–20:00
July
Jul 1 02:00–04:00 Jul 6 03:00–05:00 Jul 7 19:00–22:00 Jul 8 02:00–05:00 Jul 9 01:00–03:00 Jul 12 17:00–20:00 Jul 13 23:00–24:00 Jul 14 00:00–03:00, 17:00–19:00 Jul 15 20:00–24:00 Jul 17 02:00–05:00, 23:00–24:00 Jul 18 16:00–18:00 Jul 19 00:00–01:00, 04:00–06:00 Jul 20 04:00–08:00 Jul 22 20:00–21:00 Jul 23 04:00–07:00, 22:00–24:00 Jul 24 03:00–06:00 Jul 25 04:00–05:00, 19:00–20:00 Jul 28 20:00–23:00 Jul 29 21:00–24:00
August
Aug 1 19:00–21:00 Aug 2 03:00–04:00, 20:00–21:00 Aug 3 05:00–08:00 Aug 4 02:00–03:00, 05:00–07:00 Aug 7 20:00–22:00 Aug 8 19:00–21:00 Aug 9 05:00–06:00, 20:00–22:00 Aug 10 21:00–24:00 Aug 11 03:00–05:00 Aug 12 01:00–02:00 Aug 14 20:00–22:00 Aug 15 17:00–19:00 Aug 17 05:00–10:00 Aug 18 22:00–24:00 Aug 20 20:00–22:00 Aug 21 05:00–06:00, 23:00–24:00 Aug 23 04:00–07:00, 21:00–24:00
September
Sep 2 05:00–06:00 Sep 3 04:00–07:00 Sep 4 06:00–07:00 Sep 5 07:00–08:00, 23:00–24:00 Sep 7 05:00–06:00, 08:00–11:00 Sep 8 07:00–08:00 Sep 9 08:00–11:00 Sep 10 04:00–07:00 Sep 11 07:00–09:00 Sep 12 04:00–05:00, 23:00–24:00 Sep 13 05:00–11:00 Sep 14 03:00–10:00 Sep 15 05:00–08:00 Sep 16 06:00–09:00 Sep 18 19:00–21:00 Sep 19 07:00–09:00 Sep 20 09:00–11:00 Sep 21 08:00–12:00 Sep 22 05:00–09:00 Sep 24 22:00–24:00 Sep 25 00:00–01:00, 05:00–09:00 Sep 26 09:00–12:00 Sep 27 05:00–11:00, 21:00–23:00 Sep 28 06:00–07:00 Sep 29 16:00–18:00 Sep 30 05:00–11:00
October
Oct 1 04:00–10:00 Oct 2 04:00–09:00, 22:00–24:00 Oct 3 00:00–01:00, 16:00–17:00 Oct 4 04:00–13:00 Oct 5 06:00–07:00 Oct 6 20:00–24:00 Oct 7 23:00–24:00 Oct 8 00:00–02:00, 04:00–09:00 Oct 9 00:00–02:00, 04:00–06:00, 08:00–09:00 Oct 10 04:00–09:00 Oct 11 05:00–08:00, 10:00–13:00 Oct 12 05:00–08:00, 10:00–12:00 Oct 13 06:00–12:00 Oct 14 06:00–10:00 Oct 15 03:00–10:00 Oct 19 04:00–11:00 Oct 20 08:00–11:00 Oct 21 19:00–21:00 Oct 22 07:00–12:00 Oct 23 07:00–10:00 Oct 24 07:00–09:00, 11:00–12:00 Oct 25 08:00–09:00 Oct 26 04:00–08:00, 22:00–24:00 Oct 27 00:00–01:00 Oct 28 07:00–10:00 Oct 29 07:00–12:00 Oct 30 23:00–24:00 Oct 31 00:00–01:00
November
Nov 1 07:00–11:00 Nov 2 05:00–08:00 Nov 3 05:00–11:00 Nov 4 05:00–07:00 Nov 5 06:00–12:00 Nov 6 06:00–07:00, 09:00–10:00 Nov 7 05:00–07:00 Nov 8 05:00–08:00 Nov 10 06:00–12:00 Nov 12 04:00–10:00 Nov 16 04:00–12:00 Nov 17 21:00–24:00 Nov 18 02:00–09:00 Nov 19 21:00–24:00 Nov 21 06:00–09:00 Nov 22 06:00–13:00 Nov 26 08:00–11:00 Nov 29 06:00–07:00 Nov 30 05:00–09:00
December
Dec 1 21:00–22:00 Dec 3 17:00–19:00 Dec 9 05:00–09:00 Dec 11 01:00–03:00, 14:00–17:00, 21:00–24:00 Dec 13 05:00–09:00 Dec 14 06:00–07:00 Dec 15 19:00–23:00 Dec 16 05:00–07:00, 09:00–11:00 Dec 17 20:00–21:00 Dec 18 18:00–22:00 Dec 19 06:00–10:00, 22:00–24:00 Dec 20 00:00–01:00, 18:00–21:00 Dec 21 06:00–10:00 Dec 23 00:00–02:00, 20:00–24:00 Dec 24 03:00–05:00 Dec 26 21:00–23:00 Dec 28 06:00–09:00, 20:00–21:00 Dec 29 23:00–24:00 Dec 30 20:00–21:00 Dec 31 03:00–04:00