Most often in June, 24 days.
Highest follower count seen that year: 99,770.
January
Jan 15 23:00–24:00 Jan 16 00:00–01:00, 06:00–08:00, 22:00–24:00 Jan 17 05:00–08:00, 21:00–24:00 Jan 18 02:00–06:00 Jan 19 21:00–24:00 Jan 20 05:00–07:00, 21:00–24:00 Jan 21 04:00–07:00, 23:00–24:00 Jan 22 00:00–01:00, 04:00–07:00, 21:00–24:00 Jan 23 04:00–07:00 Jan 24 21:00–24:00 Jan 25 04:00–05:00, 22:00–24:00 Jan 26 22:00–24:00 Jan 27 00:00–01:00, 05:00–07:00, 21:00–24:00 Jan 28 00:00–01:00, 05:00–07:00, 23:00–24:00 Jan 29 00:00–02:00, 05:00–07:00, 22:00–24:00 Jan 30 00:00–02:00, 20:00–22:00 Jan 31 22:00–24:00
February
Feb 1 00:00–01:00, 04:00–05:00, 21:00–24:00 Feb 2 05:00–07:00 Feb 3 22:00–24:00 Feb 4 00:00–01:00, 04:00–07:00, 22:00–24:00 Feb 5 00:00–01:00, 05:00–08:00, 22:00–24:00 Feb 6 00:00–01:00, 05:00–07:00, 23:00–24:00 Feb 7 00:00–04:00 Feb 14 00:00–04:00 Feb 16 22:00–24:00 Feb 17 00:00–01:00, 05:00–07:00, 20:00–22:00 Feb 18 05:00–08:00 Feb 19 01:00–05:00, 21:00–24:00 Feb 20 05:00–07:00, 22:00–23:00 Feb 21 00:00–01:00, 03:00–06:00, 20:00–22:00 Feb 22 02:00–05:00 Feb 23 23:00–24:00 Feb 24 00:00–02:00, 05:00–07:00, 22:00–24:00 Feb 25 00:00–01:00, 05:00–07:00, 19:00–22:00 Feb 26 21:00–24:00 Feb 27 03:00–06:00, 21:00–24:00 Feb 28 03:00–05:00, 19:00–24:00
March
Mar 1 04:00–06:00, 21:00–24:00 Mar 2 00:00–01:00, 03:00–06:00, 22:00–24:00 Mar 3 00:00–01:00, 06:00–07:00 Mar 4 22:00–24:00 Mar 5 04:00–06:00, 20:00–24:00 Mar 6 06:00–08:00, 20:00–22:00 Mar 7 05:00–08:00 Mar 11 21:00–23:00 Mar 12 04:00–07:00 Mar 23 22:00–24:00 Mar 24 05:00–08:00, 19:00–22:00 Mar 25 22:00–24:00 Mar 26 23:00–24:00 Mar 27 00:00–01:00, 05:00–07:00, 20:00–21:00, 23:00–24:00 Mar 28 00:00–02:00, 04:00–07:00, 20:00–24:00 Mar 29 05:00–07:00, 20:00–24:00 Mar 30 05:00–07:00, 23:00–24:00 Mar 31 00:00–01:00, 05:00–07:00, 23:00–24:00
April
Apr 1 00:00–02:00, 22:00–24:00 Apr 2 03:00–05:00, 22:00–24:00 Apr 3 00:00–01:00, 03:00–05:00 Apr 4 21:00–23:00 Apr 5 21:00–24:00 Apr 6 04:00–06:00 Apr 7 05:00–07:00, 22:00–24:00 Apr 8 04:00–06:00, 22:00–24:00 Apr 9 04:00–05:00, 22:00–24:00 Apr 10 04:00–07:00 Apr 11 00:00–01:00, 22:00–24:00 Apr 12 00:00–01:00, 04:00–06:00 Apr 13 04:00–06:00, 22:00–24:00 Apr 14 04:00–07:00, 22:00–24:00 Apr 15 00:00–01:00, 05:00–07:00 Apr 16 01:00–06:00, 21:00–23:00 Apr 25 22:00–23:00 Apr 26 21:00–23:00 Apr 27 00:00–01:00, 05:00–07:00 Apr 28 22:00–24:00 Apr 29 00:00–07:00, 23:00–24:00 Apr 30 00:00–01:00, 22:00–24:00
May
May 1 00:00–01:00, 04:00–06:00, 23:00–24:00 May 2 00:00–01:00 May 6 00:00–02:00, 22:00–24:00 May 7 00:00–01:00, 04:00–05:00 May 12 22:00–24:00 May 13 00:00–01:00, 04:00–06:00, 22:00–24:00 May 14 00:00–01:00, 04:00–06:00, 22:00–24:00 May 15 00:00–01:00, 05:00–07:00, 22:00–24:00 May 16 00:00–04:00 May 20 21:00–22:00 May 21 00:00–01:00, 05:00–08:00, 22:00–24:00 May 22 04:00–06:00, 21:00–24:00 May 23 04:00–06:00, 21:00–24:00 May 24 00:00–03:00 May 25 22:00–24:00 May 26 00:00–01:00, 04:00–08:00, 22:00–24:00 May 27 00:00–01:00, 03:00–06:00, 23:00–24:00 May 28 00:00–02:00, 04:00–07:00, 22:00–24:00 May 29 00:00–01:00, 05:00–07:00, 21:00–24:00 May 30 00:00–01:00, 05:00–07:00, 21:00–24:00 May 31 00:00–01:00, 04:00–06:00
June
Jun 1 01:00–06:00, 23:00–24:00 Jun 2 00:00–02:00, 05:00–07:00 Jun 3 00:00–05:00 Jun 4 22:00–24:00 Jun 5 00:00–01:00, 05:00–06:00, 23:00–24:00 Jun 6 00:00–01:00, 05:00–08:00, 22:00–24:00 Jun 7 00:00–01:00, 04:00–07:00, 22:00–24:00 Jun 8 00:00–02:00 Jun 9 01:00–05:00, 23:00–24:00 Jun 10 00:00–01:00, 04:00–06:00, 22:00–24:00 Jun 11 04:00–06:00 Jun 12 00:00–02:00, 04:00–08:00, 22:00–24:00 Jun 13 00:00–02:00, 04:00–05:00 Jun 19 22:00–24:00 Jun 20 03:00–07:00, 23:00–24:00 Jun 21 00:00–03:00, 23:00–24:00 Jun 22 00:00–01:00 Jun 23 04:00–06:00, 23:00–24:00 Jun 24 00:00–01:00, 04:00–06:00, 21:00–24:00 Jun 25 03:00–05:00, 22:00–24:00 Jun 26 04:00–05:00, 20:00–22:00 Jun 27 20:00–24:00 Jun 29 03:00–08:00, 21:00–24:00 Jun 30 00:00–01:00, 05:00–07:00, 21:00–24:00
July
Jul 1 00:00–01:00, 19:00–22:00 Jul 2 21:00–24:00 Jul 3 00:00–04:00, 22:00–24:00 Jul 4 00:00–01:00, 05:00–08:00, 20:00–23:00 Jul 5 00:00–01:00, 04:00–07:00, 21:00–24:00 Jul 6 04:00–06:00 Jul 7 19:00–22:00 Jul 8 22:00–24:00 Jul 9 00:00–02:00, 22:00–24:00 Jul 10 00:00–01:00, 05:00–07:00, 20:00–21:00 Jul 11 01:00–02:00, 05:00–07:00 Jul 12 21:00–24:00 Jul 13 00:00–01:00, 04:00–06:00, 21:00–24:00 Jul 14 00:00–01:00, 05:00–07:00, 23:00–24:00 Jul 15 00:00–01:00, 04:00–07:00, 23:00–24:00 Jul 16 00:00–02:00, 05:00–08:00 Jul 22 20:00–22:00 Jul 23 23:00–24:00 Jul 24 00:00–01:00, 05:00–07:00, 23:00–24:00 Jul 25 00:00–01:00, 06:00–07:00, 21:00–24:00