Most often in March, 30 days.
Highest follower count seen that year: 8,708.
January
Jan 6 12:00–19:00 Jan 7 12:00–19:00 Jan 8 12:00–19:00 Jan 9 12:00–19:00 Jan 10 12:00–19:00 Jan 11 12:00–19:00 Jan 12 12:00–19:00 Jan 13 12:00–15:00, 21:00–24:00 Jan 15 13:00–19:00 Jan 17 12:00–19:00 Jan 19 12:00–19:00 Jan 20 12:00–19:00 Jan 21 13:00–19:00 Jan 22 21:00–23:00 Jan 23 00:00–03:00, 12:00–19:00 Jan 25 22:00–24:00 Jan 26 00:00–03:00, 12:00–19:00 Jan 27 20:00–24:00 Jan 28 00:00–03:00, 12:00–19:00 Jan 29 20:00–24:00 Jan 30 00:00–03:00 Jan 31 04:00–09:00, 12:00–19:00
February
Feb 3 12:00–19:00 Feb 4 19:00–24:00 Feb 5 00:00–03:00, 12:00–19:00 Feb 6 20:00–24:00 Feb 7 00:00–03:00, 20:00–24:00 Feb 8 00:00–02:00, 21:00–24:00 Feb 9 00:00–03:00, 20:00–24:00 Feb 10 00:00–03:00, 21:00–24:00 Feb 11 00:00–03:00 Feb 12 21:00–24:00 Feb 13 00:00–03:00, 21:00–24:00 Feb 14 01:00–03:00, 21:00–24:00 Feb 15 00:00–03:00, 20:00–24:00 Feb 16 00:00–03:00 Feb 17 20:00–23:00 Feb 18 00:00–03:00 Feb 19 21:00–24:00 Feb 20 00:00–03:00, 20:00–24:00 Feb 21 00:00–03:00 Feb 22 20:00–24:00 Feb 23 00:00–03:00, 20:00–24:00 Feb 24 00:00–03:00, 20:00–24:00 Feb 25 00:00–03:00, 20:00–23:00 Feb 26 01:00–03:00, 21:00–24:00 Feb 27 00:00–03:00, 21:00–24:00 Feb 28 00:00–04:00, 20:00–24:00
March
Mar 1 01:00–04:00 Mar 2 20:00–24:00 Mar 3 00:00–03:00, 21:00–23:00 Mar 4 00:00–03:00 Mar 5 22:00–23:00 Mar 6 00:00–01:00, 21:00–23:00 Mar 7 00:00–03:00, 21:00–24:00 Mar 8 00:00–03:00 Mar 9 21:00–24:00 Mar 10 00:00–03:00, 21:00–24:00 Mar 11 00:00–03:00, 22:00–24:00 Mar 12 00:00–03:00, 21:00–24:00 Mar 13 00:00–03:00, 21:00–24:00 Mar 14 00:00–03:00, 21:00–24:00 Mar 15 00:00–03:00, 21:00–24:00 Mar 16 00:00–03:00 Mar 17 21:00–23:00 Mar 18 00:00–03:00, 21:00–23:00 Mar 19 00:00–03:00, 22:00–24:00 Mar 20 00:00–02:00, 21:00–24:00 Mar 21 00:00–03:00 Mar 22 12:00–19:00 Mar 23 12:00–19:00 Mar 24 12:00–18:00 Mar 25 12:00–20:00 Mar 26 12:00–19:00 Mar 27 12:00–19:00 Mar 28 12:00–19:00 Mar 30 13:00–20:00 Mar 31 12:00–20:00
April
Apr 1 12:00–19:00 Apr 2 12:00–15:00, 17:00–19:00 Apr 3 13:00–17:00 Apr 4 13:00–19:00 Apr 5 12:00–20:00 Apr 7 12:00–18:00 Apr 9 12:00–17:00 Apr 11 12:00–20:00 Apr 12 13:00–19:00 Apr 13 12:00–19:00 Apr 14 13:00–19:00 Apr 15 13:00–20:00 Apr 17 12:00–20:00 Apr 19 12:00–19:00 Apr 20 12:00–19:00 Apr 22 12:00–19:00 Apr 23 13:00–20:00 Apr 24 12:00–20:00 Apr 25 12:00–20:00 Apr 26 12:00–19:00 Apr 27 12:00–20:00 Apr 28 12:00–20:00 Apr 29 12:00–20:00 Apr 30 12:00–19:00
May
May 3 13:00–20:00 May 4 12:00–20:00 May 5 12:00–19:00 May 6 14:00–19:00 May 8 12:00–15:00, 17:00–20:00 May 9 14:00–19:00 May 10 12:00–19:00 May 11 12:00–19:00 May 12 12:00–20:00 May 13 13:00–19:00 May 14 12:00–20:00 May 15 12:00–19:00 May 18 12:00–19:00 May 19 12:00–19:00 May 20 13:00–19:00 May 21 12:00–13:00, 16:00–19:00 May 22 12:00–19:00 May 24 12:00–19:00 May 26 04:00–18:00 May 28 04:00–11:00 May 29 04:00–11:00 May 30 04:00–10:00 May 31 04:00–11:00
June
Jun 3 04:00–11:00 Jun 4 04:00–11:00 Jun 5 05:00–12:00 Jun 6 05:00–11:00 Jun 8 04:00–11:00 Jun 9 04:00–11:00 Jun 10 05:00–11:00 Jun 11 05:00–11:00 Jun 13 05:00–12:00 Jun 15 04:00–11:00 Jun 16 04:00–12:00 Jun 18 04:00–11:00 Jun 19 04:00–11:00 Jun 21 04:00–11:00 Jun 22 04:00–11:00 Jun 24 04:00–12:00 Jun 25 04:00–11:00 Jun 26 04:00–11:00 Jun 27 05:00–10:00 Jun 28 05:00–11:00 Jun 29 04:00–11:00 Jun 30 05:00–11:00
July
Jul 1 04:00–11:00 Jul 3 04:00–11:00 Jul 5 05:00–11:00 Jul 6 04:00–11:00 Jul 7 04:00–11:00 Jul 8 04:00–11:00 Jul 9 04:00–11:00 Jul 11 05:00–11:00 Jul 12 05:00–12:00 Jul 13 05:00–11:00 Jul 14 05:00–11:00 Jul 15 08:00–12:00 Jul 16 06:00–10:00 Jul 19 04:00–11:00 Jul 20 05:00–11:00 Jul 21 05:00–06:00 Jul 23 06:00–09:00, 11:00–18:00 Jul 24 05:00–11:00 Jul 25 04:00–07:00 Jul 26 05:00–07:00, 08:00–10:00