Most often in May, 31 days.
Highest follower count seen that year: 385,128.
January
Jan 1 00:00–01:00 Jan 2 00:00–02:00, 07:00–10:00, 23:00–24:00 Jan 3 00:00–01:00 Jan 4 03:00–07:00 Jan 5 05:00–09:00, 22:00–24:00 Jan 6 00:00–03:00, 07:00–10:00 Jan 7 07:00–10:00 Jan 8 05:00–08:00, 13:00–15:00 Jan 9 15:00–19:00, 21:00–23:00
February
Feb 19 03:00–08:00 Feb 20 05:00–07:00 Feb 21 03:00–05:00 Feb 23 01:00–02:00, 06:00–09:00, 22:00–24:00 Feb 24 03:00–07:00, 23:00–24:00 Feb 25 00:00–01:00 Feb 26 04:00–08:00 Feb 27 06:00–09:00 Feb 28 08:00–10:00
March
Mar 2 01:00–04:00, 07:00–10:00, 21:00–24:00 Mar 3 04:00–07:00 Mar 4 05:00–08:00, 21:00–24:00 Mar 5 00:00–01:00 Mar 6 06:00–09:00 Mar 7 05:00–09:00 Mar 8 06:00–09:00 Mar 12 00:00–03:00, 23:00–24:00 Mar 13 00:00–04:00, 15:00–17:00, 23:00–24:00 Mar 14 00:00–02:00, 22:00–24:00 Mar 15 00:00–02:00, 20:00–22:00 Mar 16 22:00–24:00 Mar 17 00:00–01:00, 03:00–06:00, 16:00–17:00, 20:00–22:00 Mar 18 16:00–19:00 Mar 19 16:00–19:00 Mar 20 17:00–19:00 Mar 21 03:00–05:00, 16:00–19:00 Mar 22 01:00–03:00, 23:00–24:00 Mar 23 02:00–05:00, 20:00–21:00 Mar 24 01:00–04:00, 17:00–20:00 Mar 25 16:00–19:00, 23:00–24:00 Mar 26 00:00–01:00, 17:00–19:00 Mar 27 00:00–04:00, 16:00–18:00 Mar 28 01:00–03:00 Mar 29 02:00–05:00, 23:00–24:00 Mar 30 00:00–01:00, 05:00–08:00, 18:00–20:00 Mar 31 06:00–08:00
April
Apr 1 01:00–03:00, 15:00–18:00 Apr 2 01:00–05:00, 17:00–19:00 Apr 3 17:00–20:00 Apr 4 01:00–04:00, 17:00–18:00 Apr 5 22:00–24:00 Apr 6 00:00–01:00, 04:00–06:00, 21:00–24:00 Apr 7 00:00–01:00, 03:00–05:00, 16:00–18:00 Apr 8 03:00–05:00, 16:00–19:00 Apr 9 02:00–05:00 Apr 10 23:00–24:00 Apr 11 00:00–01:00, 17:00–19:00 Apr 12 18:00–20:00 Apr 13 05:00–07:00, 22:00–24:00 Apr 14 00:00–02:00, 16:00–18:00 Apr 15 00:00–03:00 Apr 16 00:00–03:00, 17:00–19:00 Apr 17 01:00–03:00, 17:00–19:00 Apr 18 03:00–08:00, 16:00–19:00 Apr 20 22:00–24:00 Apr 21 02:00–04:00 Apr 22 03:00–06:00, 23:00–24:00 Apr 23 00:00–02:00 Apr 24 02:00–04:00, 19:00–22:00 Apr 25 00:00–02:00 Apr 26 02:00–07:00 Apr 27 00:00–03:00, 23:00–24:00 Apr 28 00:00–02:00, 06:00–08:00 Apr 29 16:00–18:00
May
May 1 18:00–22:00 May 2 02:00–04:00, 18:00–19:00 May 3 23:00–24:00 May 4 04:00–07:00, 20:00–22:00 May 5 23:00–24:00 May 6 00:00–07:00 May 7 03:00–06:00 May 8 05:00–07:00 May 9 03:00–06:00 May 10 04:00–06:00 May 11 07:00–09:00, 22:00–24:00 May 12 00:00–02:00 May 13 23:00–24:00 May 14 00:00–05:00, 16:00–17:00 May 15 03:00–06:00 May 16 02:00–05:00, 22:00–24:00 May 17 00:00–03:00, 05:00–06:00, 18:00–21:00 May 18 03:00–08:00, 18:00–24:00 May 19 01:00–04:00 May 20 03:00–06:00 May 21 00:00–04:00 May 22 04:00–07:00, 21:00–24:00 May 23 00:00–06:00, 18:00–21:00 May 24 19:00–21:00 May 25 23:00–24:00 May 26 00:00–01:00 May 27 03:00–07:00 May 28 02:00–05:00 May 29 03:00–06:00 May 30 03:00–04:00 May 31 03:00–06:00, 21:00–23:00
June
Jun 1 23:00–24:00 Jun 2 00:00–06:00, 18:00–20:00 Jun 3 04:00–06:00 Jun 4 04:00–06:00 Jun 5 05:00–07:00, 23:00–24:00 Jun 6 00:00–02:00, 04:00–06:00 Jun 8 21:00–24:00 Jun 9 04:00–06:00 Jun 10 04:00–06:00 Jun 11 00:00–05:00 Jun 12 06:00–08:00 Jun 15 04:00–08:00 Jun 16 06:00–09:00, 18:00–19:00 Jun 17 04:00–06:00, 17:00–18:00 Jun 18 01:00–05:00 Jun 19 04:00–07:00 Jun 20 03:00–07:00 Jun 21 03:00–07:00 Jun 22 00:00–04:00, 07:00–09:00, 22:00–24:00 Jun 23 00:00–01:00, 03:00–06:00, 17:00–19:00 Jun 24 04:00–07:00 Jun 25 00:00–05:00
July
Jul 2 05:00–09:00 Jul 3 07:00–09:00, 23:00–24:00 Jul 4 00:00–01:00, 04:00–07:00 Jul 6 00:00–03:00, 23:00–24:00 Jul 7 00:00–01:00, 04:00–06:00 Jul 8 06:00–08:00, 16:00–19:00, 23:00–24:00 Jul 9 00:00–02:00 Jul 10 04:00–08:00 Jul 11 00:00–07:00 Jul 12 22:00–24:00 Jul 13 00:00–01:00, 06:00–09:00, 22:00–24:00 Jul 14 04:00–07:00 Jul 15 05:00–08:00 Jul 16 01:00–07:00 Jul 18 03:00–08:00 Jul 19 06:00–09:00 Jul 24 04:00–09:00, 22:00–24:00 Jul 25 00:00–06:00 Jul 26 21:00–24:00 Jul 27 00:00–04:00, 21:00–24:00 Jul 28 00:00–01:00, 14:00–18:00 Jul 29 20:00–24:00 Jul 30 00:00–01:00, 14:00–16:00
August
Aug 2 23:00–24:00 Aug 3 00:00–03:00, 19:00–24:00 Aug 4 00:00–04:00 Aug 5 19:00–22:00 Aug 6 00:00–03:00, 19:00–22:00 Aug 8 03:00–06:00, 20:00–22:00 Aug 9 20:00–24:00 Aug 10 23:00–24:00 Aug 11 03:00–05:00 Aug 12 04:00–08:00 Aug 14 03:00–06:00 Aug 15 06:00–09:00 Aug 16 07:00–09:00 Aug 17 03:00–07:00 Aug 18 00:00–04:00, 23:00–24:00 Aug 19 00:00–02:00 Aug 20 00:00–03:00, 14:00–17:00 Aug 23 21:00–23:00 Aug 24 15:00–17:00 Aug 25 23:00–24:00 Aug 26 00:00–02:00, 12:00–13:00, 19:00–22:00 Aug 27 16:00–17:00 Aug 28 15:00–17:00 Aug 29 00:00–02:00 Aug 30 20:00–24:00 Aug 31 03:00–04:00, 23:00–24:00
September
Sep 1 00:00–05:00, 16:00–17:00 Sep 2 01:00–05:00, 16:00–19:00 Sep 3 02:00–05:00, 13:00–16:00, 22:00–24:00 Sep 4 00:00–01:00, 13:00–16:00 Sep 5 02:00–05:00, 14:00–17:00 Sep 6 19:00–23:00 Sep 7 00:00–02:00, 21:00–24:00 Sep 8 01:00–05:00, 14:00–17:00 Sep 9 18:00–24:00 Sep 10 13:00–17:00 Sep 11 00:00–04:00, 10:00–14:00 Sep 14 20:00–24:00 Sep 15 00:00–05:00, 13:00–18:00 Sep 16 01:00–04:00, 23:00–24:00 Sep 17 00:00–05:00 Sep 18 19:00–20:00 Sep 19 02:00–06:00, 15:00–18:00 Sep 20 01:00–05:00, 16:00–22:00 Sep 21 21:00–24:00 Sep 22 00:00–05:00, 16:00–21:00 Sep 23 02:00–06:00, 15:00–18:00 Sep 24 00:00–03:00, 16:00–18:00 Sep 25 16:00–18:00 Sep 26 00:00–02:00 Sep 27 03:00–06:00 Sep 28 00:00–03:00, 23:00–24:00 Sep 29 00:00–02:00, 15:00–19:00 Sep 30 16:00–18:00
October
Oct 1 00:00–03:00, 16:00–17:00 Oct 6 23:00–24:00 Oct 7 00:00–04:00, 22:00–24:00 Oct 8 00:00–02:00, 14:00–17:00 Oct 9 00:00–02:00, 16:00–19:00 Oct 10 01:00–03:00 Oct 11 01:00–07:00, 19:00–21:00 Oct 13 00:00–04:00, 13:00–17:00 Oct 14 01:00–04:00, 21:00–23:00 Oct 15 00:00–02:00, 13:00–17:00 Oct 16 01:00–03:00, 14:00–19:00, 22:00–24:00 Oct 17 00:00–01:00, 20:00–24:00 Oct 18 00:00–04:00, 22:00–24:00 Oct 19 00:00–04:00, 16:00–20:00 Oct 20 02:00–04:00, 12:00–15:00, 20:00–24:00 Oct 21 19:00–22:00 Oct 22 14:00–17:00 Oct 23 15:00–17:00 Oct 24 00:00–04:00, 15:00–18:00 Oct 25 01:00–05:00, 21:00–24:00 Oct 26 00:00–01:00 Oct 27 02:00–05:00, 14:00–18:00, 22:00–24:00 Oct 28 00:00–01:00, 16:00–19:00 Oct 29 01:00–06:00, 14:00–18:00 Oct 30 00:00–04:00, 15:00–18:00 Oct 31 00:00–05:00, 15:00–18:00
November
Nov 1 04:00–07:00, 20:00–22:00 Nov 3 18:00–23:00 Nov 4 21:00–23:00 Nov 6 01:00–04:00 Nov 7 01:00–06:00 Nov 8 04:00–09:00 Nov 9 00:00–07:00, 16:00–18:00 Nov 16 23:00–24:00 Nov 17 00:00–03:00 Nov 18 01:00–03:00, 16:00–18:00 Nov 19 02:00–05:00, 17:00–20:00 Nov 20 03:00–05:00, 18:00–21:00 Nov 21 23:00–24:00 Nov 22 00:00–04:00 Nov 23 20:00–22:00 Nov 30 22:00–24:00
December
Dec 1 00:00–02:00, 15:00–18:00 Dec 2 03:00–05:00, 16:00–19:00 Dec 3 01:00–04:00, 17:00–19:00 Dec 4 04:00–06:00, 17:00–18:00 Dec 5 02:00–05:00, 19:00–22:00 Dec 6 04:00–07:00, 18:00–22:00 Dec 8 03:00–06:00, 17:00–19:00 Dec 9 00:00–04:00 Dec 10 00:00–05:00, 16:00–19:00 Dec 11 04:00–06:00, 17:00–23:00 Dec 12 04:00–07:00 Dec 13 18:00–22:00 Dec 14 22:00–24:00 Dec 16 04:00–06:00, 17:00–19:00 Dec 17 04:00–06:00, 14:00–17:00 Dec 18 02:00–05:00, 19:00–21:00 Dec 19 06:00–08:00 Dec 22 23:00–24:00 Dec 23 00:00–05:00 Dec 24 03:00–10:00 Dec 25 01:00–02:00 Dec 26 02:00–09:00, 11:00–15:00 Dec 27 02:00–07:00 Dec 28 00:00–06:00, 21:00–24:00 Dec 29 01:00–04:00, 15:00–19:00 Dec 30 21:00–23:00 Dec 31 05:00–08:00, 23:00–24:00