Most often in May, 28 days.
Highest follower count seen that year: 31,304.
January
Jan 11 17:00–24:00 Jan 12 00:00–04:00, 06:00–07:00, 20:00–24:00 Jan 13 00:00–02:00, 05:00–10:00, 17:00–23:00 Jan 14 05:00–06:00, 23:00–24:00 Jan 15 00:00–07:00, 21:00–24:00 Jan 16 00:00–01:00, 04:00–07:00 Jan 17 03:00–08:00 Jan 19 04:00–09:00, 22:00–24:00 Jan 20 00:00–06:00, 22:00–24:00 Jan 21 00:00–07:00 Jan 22 01:00–07:00 Jan 23 03:00–08:00 Jan 24 05:00–08:00 Jan 25 05:00–08:00 Jan 26 21:00–24:00 Jan 27 00:00–04:00 Jan 28 05:00–09:00 Jan 29 02:00–07:00 Jan 30 04:00–09:00 Jan 31 05:00–09:00
February
Feb 1 05:00–10:00, 23:00–24:00 Feb 2 00:00–08:00 Feb 3 04:00–07:00 Feb 4 04:00–09:00 Feb 5 03:00–09:00, 23:00–24:00 Feb 6 00:00–06:00 Feb 7 00:00–08:00 Feb 8 16:00–19:00 Feb 10 01:00–08:00 Feb 11 01:00–08:00 Feb 12 04:00–09:00 Feb 14 03:00–09:00 Feb 25 06:00–11:00 Feb 26 01:00–09:00, 20:00–22:00 Feb 27 02:00–07:00 Feb 28 02:00–09:00
March
Mar 1 01:00–09:00 Mar 2 03:00–08:00 Mar 3 03:00–09:00 Mar 4 04:00–08:00 Mar 5 02:00–08:00 Mar 6 04:00–09:00 Mar 7 02:00–07:00 Mar 10 05:00–09:00 Mar 11 04:00–10:00 Mar 12 03:00–10:00 Mar 14 04:00–10:00 Mar 15 01:00–08:00 Mar 18 04:00–10:00 Mar 19 00:00–08:00 Mar 20 01:00–09:00 Mar 21 05:00–09:00 Mar 23 03:00–07:00 Mar 24 03:00–10:00 Mar 26 03:00–12:00 Mar 27 04:00–16:00
April
Apr 7 05:00–12:00 Apr 8 00:00–08:00 Apr 9 03:00–08:00 Apr 10 04:00–10:00 Apr 11 01:00–07:00 Apr 13 03:00–09:00 Apr 15 04:00–11:00, 22:00–24:00 Apr 16 00:00–08:00 Apr 17 04:00–10:00, 22:00–24:00 Apr 18 00:00–01:00, 05:00–07:00 Apr 22 02:00–08:00 Apr 23 00:00–08:00 Apr 24 04:00–10:00, 23:00–24:00 Apr 25 00:00–06:00, 21:00–24:00 Apr 26 00:00–03:00, 23:00–24:00 Apr 27 00:00–07:00, 20:00–24:00 Apr 28 00:00–03:00, 05:00–06:00 Apr 29 05:00–10:00, 23:00–24:00 Apr 30 01:00–04:00, 06:00–07:00
May
May 1 05:00–10:00, 21:00–24:00 May 2 00:00–05:00, 22:00–24:00 May 3 00:00–01:00 May 5 04:00–08:00, 18:00–22:00 May 6 01:00–07:00, 22:00–24:00 May 7 00:00–07:00, 22:00–23:00 May 8 00:00–09:00, 17:00–23:00 May 9 03:00–08:00 May 10 00:00–10:00, 23:00–24:00 May 11 00:00–02:00, 22:00–24:00 May 12 00:00–09:00 May 13 03:00–11:00, 19:00–24:00 May 14 00:00–09:00 May 15 00:00–09:00 May 16 04:00–10:00 May 17 02:00–09:00 May 18 04:00–09:00 May 19 04:00–10:00 May 20 04:00–08:00 May 21 03:00–08:00 May 22 03:00–08:00 May 23 03:00–09:00 May 25 05:00–10:00 May 26 00:00–07:00 May 27 02:00–08:00, 20:00–22:00 May 28 05:00–08:00, 22:00–24:00 May 29 00:00–08:00 May 30 00:00–08:00
June
Jun 5 04:00–11:00 Jun 6 02:00–08:00 Jun 9 04:00–08:00, 18:00–23:00 Jun 10 04:00–09:00, 19:00–23:00 Jun 11 04:00–09:00 Jun 12 06:00–10:00 Jun 13 00:00–07:00 Jun 17 04:00–09:00 Jun 18 05:00–09:00 Jun 19 05:00–08:00 Jun 20 05:00–08:00 Jun 26 02:00–07:00 Jun 27 06:00–11:00
July
Jul 1 16:00–21:00 Jul 2 04:00–10:00 Jul 3 03:00–10:00 Jul 4 05:00–10:00 Jul 6 18:00–24:00 Jul 7 00:00–04:00, 18:00–19:00, 23:00–24:00 Jul 8 03:00–07:00, 21:00–24:00 Jul 9 00:00–08:00 Jul 10 03:00–10:00 Jul 11 04:00–10:00 Jul 12 05:00–10:00 Jul 14 22:00–24:00 Jul 15 00:00–14:00, 20:00–24:00 Jul 16 00:00–01:00, 05:00–12:00 Jul 18 03:00–10:00 Jul 19 05:00–10:00 Jul 23 15:00–24:00 Jul 24 00:00–06:00, 18:00–24:00 Jul 25 02:00–07:00, 22:00–24:00 Jul 26 00:00–07:00 Jul 27 04:00–10:00, 21:00–24:00 Jul 28 00:00–08:00 Jul 29 02:00–11:00 Jul 30 03:00–09:00, 19:00–24:00 Jul 31 00:00–07:00
August
Aug 1 02:00–09:00 Aug 3 01:00–10:00, 22:00–24:00 Aug 4 00:00–07:00 Aug 5 06:00–11:00 Aug 6 02:00–10:00 Aug 7 03:00–10:00 Aug 8 04:00–08:00 Aug 9 04:00–09:00 Aug 10 22:00–24:00 Aug 11 00:00–05:00 Aug 12 02:00–08:00 Aug 13 03:00–07:00 Aug 14 01:00–08:00 Aug 15 04:00–09:00 Aug 16 04:00–09:00 Aug 18 04:00–10:00, 22:00–23:00 Aug 19 00:00–06:00 Aug 20 05:00–09:00 Aug 21 04:00–10:00 Aug 22 05:00–11:00 Aug 24 03:00–09:00 Aug 25 04:00–10:00 Aug 26 02:00–08:00 Aug 27 04:00–09:00 Aug 28 03:00–10:00 Aug 29 01:00–08:00
September
Sep 1 04:00–10:00 Sep 2 04:00–10:00 Sep 3 04:00–09:00 Sep 5 04:00–08:00, 20:00–24:00 Sep 6 00:00–03:00 Sep 7 00:00–08:00, 22:00–24:00 Sep 8 00:00–06:00 Sep 9 02:00–08:00 Sep 10 04:00–09:00 Sep 11 04:00–11:00 Sep 12 03:00–10:00 Sep 13 05:00–10:00 Sep 16 02:00–10:00 Sep 17 04:00–10:00 Sep 18 02:00–08:00 Sep 19 02:00–09:00 Sep 22 05:00–08:00 Sep 23 05:00–09:00 Sep 24 04:00–10:00 Sep 25 03:00–09:00 Sep 26 03:00–09:00 Sep 28 02:00–09:00 Sep 29 04:00–09:00 Sep 30 04:00–07:00
October
Oct 1 03:00–11:00 Oct 2 02:00–07:00 Oct 3 02:00–09:00 Oct 4 05:00–10:00 Oct 7 03:00–10:00 Oct 8 04:00–08:00 Oct 14 03:00–08:00 Oct 15 06:00–08:00 Oct 16 05:00–08:00, 21:00–24:00 Oct 17 04:00–08:00, 18:00–24:00 Oct 18 00:00–04:00, 19:00–24:00 Oct 19 00:00–01:00, 23:00–24:00 Oct 20 00:00–06:00, 20:00–24:00 Oct 21 00:00–06:00, 18:00–20:00, 22:00–24:00 Oct 22 00:00–06:00, 18:00–24:00 Oct 23 00:00–07:00, 19:00–24:00 Oct 24 00:00–06:00, 22:00–24:00 Oct 25 00:00–06:00 Oct 26 02:00–06:00 Oct 27 20:00–24:00 Oct 28 00:00–07:00, 21:00–24:00 Oct 29 00:00–06:00 Oct 30 01:00–09:00
November
Nov 3 22:00–24:00 Nov 4 00:00–07:00, 19:00–24:00 Nov 5 00:00–07:00, 18:00–24:00 Nov 6 00:00–03:00, 21:00–24:00 Nov 7 00:00–07:00, 21:00–24:00 Nov 8 00:00–07:00 Nov 11 04:00–09:00, 16:00–24:00 Nov 12 00:00–07:00 Nov 13 16:00–24:00 Nov 14 00:00–04:00, 16:00–24:00 Nov 15 00:00–04:00 Nov 17 23:00–24:00 Nov 18 00:00–06:00, 23:00–24:00 Nov 19 00:00–06:00 Nov 20 02:00–07:00, 16:00–23:00 Nov 25 23:00–24:00 Nov 26 00:00–01:00, 03:00–09:00 Nov 27 05:00–09:00 Nov 28 05:00–10:00 Nov 29 04:00–10:00 Nov 30 05:00–10:00, 23:00–24:00
December
Dec 1 00:00–08:00, 23:00–24:00 Dec 2 00:00–07:00 Dec 3 05:00–11:00 Dec 5 04:00–21:00 Dec 6 03:00–18:00 Dec 8 16:00–24:00 Dec 9 00:00–01:00, 21:00–24:00 Dec 10 00:00–07:00 Dec 11 01:00–09:00 Dec 12 02:00–08:00 Dec 13 04:00–05:00, 21:00–24:00 Dec 14 00:00–02:00 Dec 15 03:00–22:00 Dec 16 04:00–08:00, 10:00–18:00, 21:00–24:00 Dec 17 00:00–12:00 Dec 18 02:00–10:00 Dec 19 03:00–24:00 Dec 20 00:00–10:00, 22:00–24:00 Dec 21 00:00–08:00, 22:00–24:00 Dec 22 00:00–06:00 Dec 24 07:00–12:00, 14:00–24:00 Dec 26 01:00–10:00 Dec 27 05:00–11:00, 19:00–24:00 Dec 28 00:00–03:00 Dec 29 07:00–09:00, 23:00–24:00 Dec 30 00:00–05:00 Dec 31 04:00–07:00