Most often in January, 29 days.
Highest follower count seen that year: 2,020.
January
Jan 2 11:00–16:00 Jan 3 11:00–16:00 Jan 4 11:00–16:00 Jan 5 11:00–16:00 Jan 6 11:00–15:00 Jan 7 12:00–16:00 Jan 8 11:00–16:00 Jan 9 11:00–16:00 Jan 10 18:00–23:00 Jan 11 11:00–16:00 Jan 12 12:00–16:00 Jan 13 12:00–16:00 Jan 14 12:00–14:00, 19:00–22:00 Jan 15 12:00–16:00 Jan 16 12:00–15:00 Jan 17 12:00–17:00 Jan 18 12:00–16:00 Jan 19 23:00–24:00 Jan 20 00:00–03:00 Jan 21 12:00–17:00 Jan 22 12:00–15:00, 20:00–22:00 Jan 23 12:00–16:00 Jan 25 14:00–18:00 Jan 26 12:00–15:00 Jan 27 12:00–16:00 Jan 28 11:00–15:00, 19:00–21:00 Jan 29 11:00–16:00 Jan 30 12:00–16:00 Jan 31 18:00–23:00
February
Feb 1 17:00–21:00 Feb 2 12:00–17:00 Feb 3 13:00–18:00 Feb 4 12:00–16:00 Feb 5 12:00–16:00 Feb 6 12:00–16:00 Feb 8 11:00–16:00 Feb 9 12:00–17:00 Feb 10 12:00–16:00 Feb 11 00:00–02:00, 12:00–16:00 Feb 12 19:00–23:00 Feb 13 12:00–17:00 Feb 14 13:00–17:00 Feb 16 12:00–16:00 Feb 17 13:00–17:00 Feb 19 11:00–16:00 Feb 20 13:00–17:00 Feb 21 13:00–18:00 Feb 22 12:00–16:00 Feb 23 12:00–16:00 Feb 24 12:00–16:00 Feb 25 11:00–16:00 Feb 26 12:00–16:00 Feb 27 12:00–17:00 Feb 28 12:00–17:00
March
Mar 1 13:00–17:00 Mar 2 12:00–17:00 Mar 3 11:00–16:00 Mar 4 12:00–16:00 Mar 5 12:00–16:00 Mar 6 12:00–17:00 Mar 7 11:00–16:00 Mar 8 11:00–16:00 Mar 10 11:00–16:00 Mar 11 11:00–17:00 Mar 12 12:00–18:00 Mar 13 12:00–16:00 Mar 15 13:00–18:00 Mar 16 11:00–16:00 Mar 17 14:00–18:00 Mar 19 12:00–16:00 Mar 20 11:00–15:00 Mar 21 12:00–16:00 Mar 22 12:00–16:00 Mar 23 12:00–16:00 Mar 24 12:00–17:00 Mar 25 13:00–17:00 Mar 26 19:00–24:00 Mar 27 12:00–15:00 Mar 28 17:00–22:00 Mar 29 12:00–17:00 Mar 30 14:00–18:00 Mar 31 12:00–16:00
April
Apr 1 12:00–17:00 Apr 4 11:00–16:00 Apr 5 11:00–16:00 Apr 6 12:00–16:00 Apr 7 12:00–16:00 Apr 8 12:00–16:00 Apr 9 12:00–16:00 Apr 10 11:00–15:00 Apr 11 12:00–17:00 Apr 12 12:00–16:00 Apr 13 20:00–23:00 Apr 14 11:00–16:00 Apr 15 16:00–20:00 Apr 16 12:00–17:00 Apr 17 13:00–17:00 Apr 18 12:00–17:00 Apr 21 12:00–13:00, 15:00–16:00 Apr 22 20:00–24:00 Apr 23 12:00–17:00 Apr 24 22:00–24:00 Apr 25 00:00–03:00, 14:00–18:00 Apr 26 13:00–17:00 Apr 27 22:00–24:00 Apr 28 00:00–02:00, 23:00–24:00 Apr 29 00:00–03:00, 23:00–24:00 Apr 30 00:00–03:00, 22:00–24:00
May
May 1 00:00–02:00, 13:00–17:00 May 3 22:00–24:00 May 4 00:00–02:00, 21:00–24:00 May 5 00:00–01:00, 22:00–24:00 May 6 00:00–02:00 May 7 01:00–05:00, 12:00–16:00 May 8 12:00–15:00 May 10 14:00–18:00 May 11 19:00–23:00 May 12 11:00–16:00 May 13 20:00–22:00 May 14 19:00–21:00 May 18 12:00–16:00, 21:00–24:00 May 19 12:00–17:00, 22:00–23:00 May 20 12:00–16:00 May 21 12:00–13:00, 23:00–24:00 May 22 00:00–01:00, 20:00–24:00 May 23 00:00–01:00, 12:00–17:00, 21:00–24:00 May 24 14:00–18:00 May 25 19:00–24:00
June
Jun 16 19:00–24:00 Jun 17 13:00–17:00 Jun 18 12:00–17:00 Jun 19 12:00–16:00 Jun 21 00:00–04:00, 19:00–24:00 Jun 23 13:00–14:00 Jun 26 20:00–23:00 Jun 27 11:00–18:00 Jun 28 12:00–16:00 Jun 29 11:00–16:00 Jun 30 15:00–16:00
July
Jul 1 12:00–16:00 Jul 2 00:00–04:00 Jul 3 11:00–15:00 Jul 4 12:00–13:00, 15:00–18:00 Jul 5 14:00–15:00 Jul 6 11:00–15:00 Jul 8 13:00–15:00 Jul 9 12:00–16:00 Jul 10 14:00–15:00 Jul 11 12:00–17:00 Jul 12 01:00–02:00, 12:00–17:00 Jul 13 12:00–17:00 Jul 14 12:00–15:00 Jul 16 12:00–14:00 Jul 17 12:00–14:00 Jul 18 13:00–15:00 Jul 19 12:00–15:00 Jul 20 13:00–16:00, 18:00–20:00 Jul 21 12:00–15:00 Jul 22 12:00–15:00 Jul 24 12:00–14:00 Jul 25 12:00–14:00 Jul 26 13:00–14:00, 15:00–16:00