Most often in June, 28 days.
Highest follower count seen that year: 15,469.
January
Jan 21 16:00–17:00
February
Feb 11 22:00–23:00 Feb 12 20:00–24:00 Feb 13 16:00–17:00, 20:00–24:00 Feb 14 19:00–21:00 Feb 16 20:00–24:00 Feb 17 00:00–02:00, 21:00–24:00 Feb 18 00:00–02:00, 21:00–24:00 Feb 19 12:00–13:00, 22:00–24:00 Feb 20 00:00–02:00 Feb 23 16:00–18:00 Feb 24 21:00–24:00 Feb 25 23:00–24:00 Feb 26 00:00–02:00, 20:00–23:00 Feb 27 22:00–24:00 Feb 28 00:00–02:00, 13:00–15:00, 19:00–24:00
March
Mar 1 00:00–01:00 Mar 2 14:00–16:00 Mar 3 20:00–24:00 Mar 4 00:00–01:00, 19:00–24:00 Mar 6 20:00–24:00 Mar 7 00:00–06:00 Mar 9 19:00–24:00 Mar 10 00:00–01:00, 14:00–16:00, 21:00–24:00 Mar 11 00:00–01:00, 22:00–24:00 Mar 12 00:00–01:00, 14:00–16:00 Mar 17 20:00–24:00 Mar 18 00:00–02:00 Mar 19 20:00–24:00 Mar 20 00:00–01:00, 21:00–24:00 Mar 21 00:00–02:00 Mar 22 22:00–24:00 Mar 23 00:00–06:00, 21:00–24:00 Mar 24 00:00–02:00, 21:00–24:00 Mar 25 00:00–05:00, 22:00–24:00 Mar 26 00:00–05:00 Mar 28 01:00–06:00 Mar 29 21:00–24:00 Mar 30 00:00–05:00 Mar 31 01:00–05:00
April
Apr 1 22:00–24:00 Apr 2 00:00–07:00, 22:00–24:00 Apr 3 00:00–05:00 Apr 4 01:00–04:00 Apr 5 02:00–08:00 Apr 6 17:00–24:00 Apr 7 00:00–03:00 Apr 9 11:00–15:00, 22:00–24:00 Apr 10 17:00–19:00
May
May 8 00:00–04:00, 19:00–23:00 May 9 03:00–05:00, 20:00–24:00 May 10 00:00–05:00, 20:00–24:00 May 11 00:00–04:00, 22:00–24:00 May 12 00:00–04:00 May 13 21:00–24:00 May 14 00:00–03:00 May 16 01:00–05:00, 07:00–12:00 May 17 16:00–22:00 May 18 17:00–24:00 May 19 00:00–01:00, 18:00–23:00 May 20 08:00–12:00 May 21 09:00–14:00, 16:00–22:00 May 22 09:00–24:00 May 23 19:00–22:00 May 24 12:00–23:00 May 25 13:00–17:00, 20:00–23:00 May 26 20:00–24:00 May 27 00:00–01:00, 17:00–23:00 May 28 01:00–03:00, 18:00–21:00 May 29 18:00–24:00 May 30 00:00–02:00, 18:00–22:00 May 31 00:00–02:00, 20:00–24:00
June
Jun 1 19:00–24:00 Jun 2 00:00–02:00, 18:00–24:00 Jun 3 00:00–01:00, 20:00–24:00 Jun 4 00:00–04:00, 19:00–24:00 Jun 5 00:00–03:00, 20:00–24:00 Jun 6 01:00–04:00, 18:00–24:00 Jun 7 00:00–04:00, 20:00–24:00 Jun 8 00:00–01:00, 19:00–24:00 Jun 9 00:00–03:00, 18:00–24:00 Jun 10 00:00–03:00, 20:00–23:00 Jun 11 00:00–02:00 Jun 12 21:00–24:00 Jun 13 00:00–06:00 Jun 15 21:00–24:00 Jun 16 00:00–03:00, 19:00–24:00 Jun 17 00:00–04:00, 11:00–14:00, 20:00–23:00 Jun 18 13:00–17:00, 22:00–24:00 Jun 19 00:00–01:00, 18:00–23:00 Jun 20 00:00–01:00, 03:00–04:00 Jun 21 18:00–24:00 Jun 22 00:00–03:00 Jun 24 20:00–24:00 Jun 25 00:00–02:00, 19:00–20:00 Jun 26 00:00–04:00, 22:00–24:00 Jun 27 00:00–04:00, 21:00–24:00 Jun 28 00:00–02:00, 21:00–24:00 Jun 29 00:00–04:00, 12:00–17:00, 19:00–24:00 Jun 30 22:00–24:00
July
Jul 1 12:00–16:00, 21:00–24:00 Jul 2 00:00–02:00 Jul 3 09:00–14:00, 17:00–24:00 Jul 4 00:00–03:00 Jul 5 14:00–18:00, 20:00–24:00 Jul 6 00:00–05:00 Jul 7 16:00–17:00, 21:00–24:00 Jul 8 00:00–03:00, 21:00–24:00 Jul 9 01:00–03:00, 18:00–24:00 Jul 10 00:00–02:00, 20:00–24:00 Jul 11 15:00–23:00 Jul 12 14:00–17:00, 19:00–22:00 Jul 13 17:00–22:00 Jul 14 00:00–03:00, 20:00–24:00 Jul 15 18:00–21:00, 23:00–24:00 Jul 16 00:00–01:00, 20:00–24:00 Jul 17 00:00–01:00, 14:00–16:00 Jul 18 14:00–17:00, 20:00–24:00 Jul 19 15:00–17:00, 19:00–24:00 Jul 20 00:00–03:00, 19:00–24:00 Jul 21 00:00–03:00, 14:00–24:00 Jul 22 00:00–04:00, 19:00–24:00 Jul 23 00:00–01:00, 18:00–24:00 Jul 24 00:00–02:00, 12:00–24:00 Jul 25 18:00–24:00 Jul 26 00:00–01:00, 12:00–17:00, 18:00–23:00