Most often in March, 27 days.
Highest follower count seen that year: 14,382.
January
Jan 1 17:00–20:00 Jan 2 10:00–11:00 Jan 4 08:00–09:00 Jan 5 10:00–12:00 Jan 6 11:00–13:00, 19:00–20:00 Jan 7 14:00–21:00 Jan 8 11:00–12:00, 20:00–21:00, 23:00–24:00 Jan 9 05:00–07:00, 16:00–18:00 Jan 10 08:00–09:00 Jan 11 02:00–03:00, 18:00–20:00 Jan 13 01:00–03:00, 19:00–21:00 Jan 14 03:00–04:00, 21:00–22:00 Jan 16 04:00–06:00 Jan 17 05:00–06:00 Jan 19 04:00–06:00 Jan 20 06:00–07:00 Jan 21 04:00–05:00, 09:00–10:00 Jan 22 04:00–05:00, 09:00–10:00 Jan 23 08:00–10:00 Jan 24 08:00–09:00, 15:00–17:00 Jan 26 09:00–11:00, 21:00–22:00 Jan 27 09:00–11:00, 18:00–19:00 Jan 28 18:00–19:00, 23:00–24:00 Jan 29 09:00–12:00, 19:00–20:00, 22:00–23:00
February
Feb 1 09:00–11:00, 18:00–20:00 Feb 2 13:00–16:00 Feb 3 22:00–24:00 Feb 4 10:00–12:00 Feb 5 16:00–18:00, 20:00–23:00 Feb 7 02:00–03:00, 21:00–22:00 Feb 9 11:00–12:00, 17:00–24:00 Feb 10 00:00–01:00, 18:00–20:00, 22:00–23:00 Feb 13 06:00–07:00, 20:00–24:00 Feb 14 05:00–06:00 Feb 16 00:00–04:00, 16:00–19:00 Feb 18 01:00–02:00, 21:00–22:00 Feb 19 14:00–16:00, 18:00–22:00 Feb 20 05:00–06:00, 22:00–24:00 Feb 21 21:00–23:00 Feb 23 00:00–02:00 Feb 24 04:00–06:00, 10:00–12:00 Feb 25 04:00–09:00, 18:00–19:00 Feb 26 07:00–08:00, 12:00–14:00 Feb 27 20:00–22:00 Feb 28 01:00–05:00, 09:00–10:00
March
Mar 1 18:00–19:00 Mar 2 07:00–10:00 Mar 3 11:00–13:00, 21:00–22:00 Mar 7 23:00–24:00 Mar 8 00:00–01:00, 09:00–11:00, 18:00–20:00 Mar 9 00:00–01:00, 09:00–11:00, 18:00–20:00 Mar 10 07:00–11:00, 21:00–23:00 Mar 11 09:00–10:00 Mar 12 00:00–01:00, 09:00–12:00, 18:00–20:00 Mar 13 18:00–21:00 Mar 14 01:00–02:00, 08:00–10:00 Mar 15 17:00–19:00 Mar 16 11:00–12:00, 20:00–22:00 Mar 17 01:00–02:00, 09:00–11:00, 18:00–20:00 Mar 18 01:00–02:00, 18:00–19:00, 23:00–24:00 Mar 19 05:00–07:00, 20:00–23:00 Mar 20 20:00–21:00 Mar 21 00:00–01:00, 12:00–14:00 Mar 22 22:00–24:00 Mar 23 10:00–11:00, 23:00–24:00 Mar 24 05:00–07:00, 19:00–20:00, 22:00–24:00 Mar 25 21:00–23:00 Mar 26 03:00–05:00 Mar 28 05:00–06:00 Mar 29 02:00–04:00 Mar 30 01:00–03:00, 10:00–11:00, 17:00–18:00 Mar 31 01:00–02:00, 07:00–08:00
April
Apr 1 23:00–24:00 Apr 2 09:00–11:00, 13:00–14:00 Apr 3 05:00–06:00, 10:00–12:00 Apr 5 01:00–02:00, 10:00–11:00 Apr 8 11:00–12:00 Apr 9 10:00–11:00 Apr 10 07:00–10:00 Apr 12 16:00–17:00, 23:00–24:00 Apr 13 00:00–01:00, 07:00–09:00 Apr 14 06:00–09:00, 23:00–24:00 Apr 15 04:00–06:00, 11:00–12:00 Apr 16 13:00–14:00, 18:00–19:00, 22:00–23:00 Apr 17 11:00–12:00, 17:00–19:00 Apr 18 10:00–11:00, 22:00–23:00 Apr 19 18:00–20:00, 22:00–23:00 Apr 20 06:00–07:00, 19:00–20:00 Apr 22 07:00–10:00 Apr 24 18:00–19:00 Apr 26 17:00–18:00 Apr 27 11:00–13:00, 20:00–22:00 Apr 28 04:00–05:00, 20:00–22:00 Apr 30 12:00–15:00, 20:00–23:00
May
May 1 01:00–03:00, 22:00–23:00 May 3 07:00–08:00 May 5 03:00–04:00 May 6 23:00–24:00 May 7 05:00–06:00 May 8 05:00–08:00 May 10 03:00–06:00 May 11 09:00–12:00 May 12 06:00–08:00, 18:00–20:00 May 13 05:00–07:00, 17:00–18:00 May 14 01:00–02:00, 19:00–20:00 May 15 09:00–13:00 May 16 05:00–08:00, 18:00–20:00 May 18 07:00–09:00, 18:00–20:00, 22:00–23:00 May 19 04:00–06:00, 20:00–21:00 May 20 05:00–08:00, 10:00–11:00, 18:00–19:00 May 21 08:00–10:00, 19:00–20:00 May 22 17:00–18:00, 23:00–24:00 May 24 00:00–01:00, 09:00–11:00, 15:00–17:00, 21:00–23:00 May 25 10:00–11:00, 15:00–17:00, 20:00–21:00 May 26 20:00–22:00 May 27 12:00–13:00 May 28 11:00–12:00, 17:00–18:00 May 29 10:00–14:00, 21:00–22:00 May 30 17:00–18:00, 21:00–23:00 May 31 04:00–05:00, 18:00–20:00
June
Jun 1 09:00–11:00, 16:00–17:00, 19:00–20:00 Jun 2 00:00–01:00, 20:00–22:00 Jun 3 05:00–06:00, 18:00–21:00 Jun 4 07:00–08:00, 18:00–19:00, 23:00–24:00 Jun 5 00:00–01:00, 23:00–24:00 Jun 6 00:00–02:00 Jun 7 01:00–03:00 Jun 8 00:00–01:00, 18:00–19:00, 23:00–24:00 Jun 10 18:00–19:00 Jun 11 02:00–03:00 Jun 12 04:00–07:00 Jun 13 03:00–04:00 Jun 15 04:00–06:00 Jun 16 02:00–03:00 Jun 17 04:00–05:00, 09:00–11:00 Jun 20 09:00–11:00, 14:00–15:00 Jun 21 06:00–07:00, 09:00–10:00 Jun 22 04:00–06:00, 09:00–10:00 Jun 23 06:00–07:00, 12:00–13:00, 23:00–24:00 Jun 24 00:00–01:00, 09:00–10:00, 12:00–13:00 Jun 25 00:00–02:00, 20:00–22:00 Jun 26 06:00–07:00, 09:00–11:00, 19:00–20:00 Jun 28 05:00–10:00 Jun 29 04:00–06:00, 12:00–14:00 Jun 30 05:00–07:00, 23:00–24:00
July
Jul 1 07:00–08:00, 11:00–12:00, 14:00–15:00 Jul 3 08:00–10:00 Jul 4 02:00–03:00, 08:00–09:00, 13:00–14:00 Jul 5 08:00–10:00 Jul 6 06:00–07:00, 09:00–11:00, 14:00–15:00 Jul 7 01:00–02:00, 10:00–11:00 Jul 8 00:00–01:00, 08:00–09:00, 11:00–12:00, 15:00–16:00 Jul 9 00:00–01:00, 06:00–08:00, 10:00–11:00 Jul 10 04:00–05:00, 17:00–18:00 Jul 11 01:00–03:00, 07:00–08:00, 17:00–18:00 Jul 12 01:00–02:00, 06:00–08:00 Jul 13 11:00–14:00, 17:00–19:00 Jul 15 00:00–01:00, 08:00–09:00, 18:00–19:00, 23:00–24:00 Jul 16 06:00–07:00, 10:00–11:00, 15:00–16:00, 18:00–19:00, 22:00–24:00 Jul 17 03:00–04:00, 06:00–07:00, 16:00–17:00 Jul 18 02:00–05:00, 07:00–08:00, 12:00–13:00 Jul 19 06:00–07:00 Jul 21 05:00–07:00, 12:00–13:00, 15:00–17:00 Jul 22 14:00–15:00, 17:00–19:00 Jul 23 07:00–08:00, 23:00–24:00 Jul 24 09:00–10:00 Jul 25 11:00–15:00 Jul 26 03:00–04:00, 12:00–14:00 Jul 27 14:00–15:00