Most often in January, 28 days.
Highest follower count seen that year: 16,164.
January
Jan 2 13:00–16:00, 20:00–22:00 Jan 3 18:00–22:00 Jan 5 14:00–17:00, 22:00–24:00 Jan 6 16:00–19:00 Jan 7 14:00–17:00 Jan 8 13:00–14:00, 21:00–22:00 Jan 9 12:00–14:00, 16:00–20:00 Jan 10 13:00–14:00, 17:00–21:00 Jan 11 13:00–15:00, 20:00–21:00 Jan 12 13:00–16:00 Jan 13 14:00–17:00 Jan 14 20:00–22:00 Jan 15 12:00–17:00 Jan 16 01:00–03:00, 13:00–15:00 Jan 17 13:00–17:00 Jan 18 22:00–23:00 Jan 19 00:00–01:00, 21:00–23:00 Jan 20 13:00–19:00 Jan 21 21:00–23:00 Jan 22 12:00–15:00 Jan 23 19:00–24:00 Jan 24 12:00–15:00, 20:00–23:00 Jan 26 07:00–10:00 Jan 27 21:00–24:00 Jan 28 00:00–02:00, 18:00–21:00 Jan 29 11:00–14:00, 21:00–22:00 Jan 30 14:00–16:00, 22:00–23:00 Jan 31 17:00–20:00
February
Feb 1 04:00–05:00 Feb 2 10:00–14:00, 17:00–18:00, 23:00–24:00 Feb 3 14:00–15:00 Feb 4 01:00–02:00, 14:00–16:00, 22:00–24:00 Feb 5 00:00–01:00, 15:00–16:00, 20:00–24:00 Feb 6 11:00–15:00, 20:00–21:00 Feb 7 20:00–22:00 Feb 8 15:00–19:00 Feb 9 23:00–24:00 Feb 10 00:00–02:00, 13:00–17:00 Feb 12 14:00–18:00 Feb 13 18:00–19:00, 21:00–23:00 Feb 14 15:00–18:00 Feb 15 12:00–15:00, 22:00–24:00 Feb 16 13:00–17:00 Feb 19 14:00–17:00 Feb 20 23:00–24:00 Feb 21 13:00–17:00 Feb 22 03:00–04:00, 19:00–22:00 Feb 23 13:00–18:00 Feb 24 13:00–14:00 Feb 26 13:00–17:00 Feb 27 20:00–22:00 Feb 28 05:00–06:00, 20:00–21:00
March
Mar 1 22:00–24:00 Mar 2 13:00–15:00, 18:00–20:00 Mar 3 13:00–15:00 Mar 4 20:00–22:00 Mar 5 13:00–14:00, 16:00–19:00 Mar 6 00:00–04:00 Mar 7 18:00–19:00, 21:00–24:00 Mar 8 00:00–01:00 Mar 9 12:00–16:00 Mar 10 01:00–03:00, 21:00–23:00 Mar 11 02:00–04:00 Mar 12 01:00–02:00, 21:00–24:00 Mar 14 14:00–16:00, 22:00–23:00 Mar 15 13:00–17:00 Mar 16 12:00–14:00, 19:00–20:00 Mar 17 14:00–15:00 Mar 19 13:00–17:00, 23:00–24:00 Mar 20 00:00–01:00, 04:00–05:00 Mar 21 14:00–16:00, 20:00–21:00 Mar 22 00:00–03:00, 14:00–16:00 Mar 23 11:00–14:00, 16:00–19:00 Mar 24 01:00–02:00, 18:00–21:00 Mar 25 00:00–01:00, 20:00–21:00 Mar 26 15:00–18:00, 21:00–23:00 Mar 27 02:00–03:00 Mar 28 00:00–01:00, 13:00–18:00, 21:00–24:00 Mar 30 19:00–22:00 Mar 31 00:00–03:00, 13:00–17:00, 23:00–24:00
April
Apr 1 00:00–01:00, 20:00–21:00, 23:00–24:00 Apr 2 22:00–24:00 Apr 4 19:00–21:00, 23:00–24:00 Apr 5 20:00–23:00 Apr 6 11:00–14:00, 22:00–23:00 Apr 7 13:00–15:00, 18:00–20:00 Apr 8 00:00–02:00, 12:00–13:00 Apr 9 14:00–16:00 Apr 10 00:00–01:00, 11:00–13:00 Apr 11 13:00–15:00 Apr 13 12:00–15:00, 22:00–23:00 Apr 15 00:00–01:00, 12:00–15:00 Apr 16 12:00–15:00, 17:00–20:00, 23:00–24:00 Apr 17 13:00–16:00, 21:00–22:00 Apr 19 22:00–24:00 Apr 20 00:00–01:00, 13:00–17:00, 21:00–24:00 Apr 21 00:00–01:00, 15:00–16:00 Apr 22 13:00–16:00, 18:00–20:00 Apr 23 00:00–01:00, 12:00–14:00, 22:00–23:00 Apr 24 12:00–14:00, 16:00–19:00, 23:00–24:00 Apr 25 13:00–15:00, 19:00–21:00 Apr 26 04:00–05:00 Apr 27 00:00–01:00, 12:00–16:00, 23:00–24:00 Apr 28 00:00–01:00, 12:00–16:00, 23:00–24:00 Apr 29 14:00–16:00, 23:00–24:00 Apr 30 12:00–15:00
May
May 1 15:00–16:00 May 2 13:00–17:00 May 3 13:00–15:00, 21:00–22:00 May 4 16:00–17:00, 23:00–24:00 May 5 22:00–23:00 May 6 12:00–13:00 May 7 14:00–15:00 May 11 00:00–01:00, 15:00–17:00 May 12 12:00–15:00 May 13 13:00–17:00 May 14 15:00–17:00 May 15 12:00–14:00 May 16 21:00–24:00 May 17 15:00–16:00 May 18 13:00–14:00 May 20 14:00–16:00 May 22 14:00–16:00 May 23 13:00–16:00 May 24 12:00–14:00 May 25 14:00–17:00 May 26 12:00–15:00 May 27 14:00–16:00 May 28 14:00–15:00 May 29 14:00–15:00, 23:00–24:00 May 30 13:00–15:00
June
Jun 25 16:00–17:00, 23:00–24:00 Jun 26 13:00–14:00, 18:00–20:00 Jun 28 13:00–16:00 Jun 29 14:00–17:00, 21:00–24:00 Jun 30 00:00–01:00, 14:00–16:00, 23:00–24:00
July
Jul 1 00:00–01:00, 14:00–15:00 Jul 2 12:00–15:00 Jul 3 13:00–14:00 Jul 4 14:00–16:00, 20:00–22:00 Jul 5 22:00–23:00 Jul 6 12:00–15:00 Jul 8 15:00–17:00 Jul 10 13:00–19:00, 22:00–24:00 Jul 11 14:00–16:00, 19:00–23:00 Jul 12 13:00–15:00 Jul 13 12:00–15:00 Jul 14 13:00–15:00, 21:00–23:00 Jul 15 14:00–16:00, 23:00–24:00 Jul 16 00:00–02:00, 15:00–16:00, 23:00–24:00 Jul 17 00:00–01:00 Jul 18 00:00–02:00, 16:00–17:00, 20:00–22:00 Jul 19 01:00–02:00, 23:00–24:00 Jul 20 00:00–01:00, 15:00–20:00 Jul 21 16:00–18:00, 22:00–24:00 Jul 22 00:00–01:00, 17:00–19:00 Jul 23 15:00–18:00 Jul 24 01:00–05:00, 14:00–17:00, 20:00–22:00 Jul 25 13:00–15:00, 20:00–21:00 Jul 26 15:00–18:00 Jul 27 00:00–02:00, 14:00–15:00