Most often in March, 25 days.
Highest follower count seen that year: 159,221.
January
Jan 7 14:00–17:00, 21:00–23:00 Jan 8 12:00–17:00, 21:00–23:00 Jan 9 12:00–15:00 Jan 10 11:00–13:00, 15:00–17:00 Jan 12 11:00–13:00, 15:00–18:00, 21:00–23:00 Jan 13 10:00–12:00, 14:00–17:00, 22:00–24:00 Jan 14 11:00–13:00, 17:00–18:00 Jan 15 16:00–18:00, 21:00–23:00 Jan 16 13:00–17:00 Jan 19 13:00–17:00, 20:00–22:00 Jan 20 10:00–12:00, 15:00–17:00 Jan 21 13:00–15:00 Jan 22 11:00–13:00, 15:00–17:00 Jan 23 11:00–14:00, 16:00–18:00 Jan 26 13:00–15:00 Jan 27 12:00–15:00, 20:00–22:00 Jan 28 13:00–15:00
February
Feb 1 15:00–17:00 Feb 2 13:00–16:00, 21:00–23:00 Feb 3 10:00–17:00, 21:00–22:00 Feb 4 15:00–18:00, 22:00–24:00 Feb 5 11:00–14:00, 16:00–17:00 Feb 6 15:00–17:00 Feb 8 14:00–17:00 Feb 9 13:00–16:00, 20:00–22:00 Feb 10 13:00–16:00, 21:00–23:00 Feb 11 12:00–16:00, 22:00–23:00 Feb 12 12:00–15:00, 20:00–22:00 Feb 13 13:00–16:00 Feb 14 16:00–20:00 Feb 16 12:00–16:00, 21:00–23:00 Feb 17 15:00–18:00, 21:00–23:00 Feb 18 15:00–17:00, 20:00–23:00 Feb 19 11:00–17:00 Feb 24 13:00–17:00, 21:00–23:00 Feb 25 11:00–13:00, 15:00–17:00, 20:00–22:00 Feb 26 11:00–16:00 Feb 27 12:00–16:00
March
Mar 2 11:00–16:00, 19:00–22:00 Mar 3 09:00–11:00, 14:00–17:00, 20:00–22:00 Mar 4 12:00–17:00, 20:00–22:00 Mar 5 11:00–17:00 Mar 6 15:00–18:00 Mar 8 22:00–23:00 Mar 9 10:00–13:00, 15:00–17:00, 21:00–23:00 Mar 10 12:00–17:00, 20:00–22:00 Mar 11 10:00–15:00 Mar 12 12:00–17:00, 21:00–22:00 Mar 13 13:00–17:00 Mar 14 15:00–17:00 Mar 15 13:00–15:00, 22:00–23:00 Mar 16 12:00–16:00, 21:00–23:00 Mar 17 13:00–16:00 Mar 18 13:00–14:00, 16:00–17:00, 22:00–24:00 Mar 19 20:00–23:00 Mar 20 10:00–16:00 Mar 21 22:00–24:00 Mar 23 15:00–17:00, 20:00–23:00 Mar 24 11:00–18:00 Mar 27 11:00–17:00, 20:00–23:00 Mar 29 13:00–15:00 Mar 30 09:00–11:00, 14:00–15:00, 20:00–23:00 Mar 31 10:00–12:00, 14:00–16:00, 20:00–22:00
April
Apr 1 10:00–15:00, 20:00–21:00 Apr 2 10:00–12:00, 14:00–16:00 Apr 3 11:00–15:00 Apr 5 13:00–14:00 Apr 6 10:00–15:00, 19:00–21:00 Apr 7 12:00–16:00, 20:00–22:00 Apr 8 11:00–13:00, 20:00–22:00 Apr 9 14:00–16:00 Apr 10 12:00–16:00 Apr 11 11:00–16:00 Apr 13 12:00–15:00, 20:00–22:00 Apr 14 13:00–15:00, 20:00–22:00 Apr 15 11:00–16:00, 21:00–22:00 Apr 16 11:00–16:00 Apr 17 12:00–15:00 Apr 18 13:00–16:00 Apr 21 12:00–16:00, 19:00–21:00 Apr 22 10:00–15:00 Apr 23 11:00–16:00, 20:00–21:00 Apr 24 13:00–16:00, 20:00–22:00 Apr 25 14:00–16:00, 19:00–21:00 Apr 26 11:00–14:00 Apr 27 13:00–15:00 Apr 28 12:00–16:00, 21:00–22:00 Apr 29 14:00–16:00
May
May 6 12:00–17:00, 20:00–23:00 May 7 13:00–16:00, 20:00–22:00 May 8 12:00–14:00 May 9 12:00–15:00, 20:00–22:00 May 11 13:00–17:00, 21:00–22:00 May 12 13:00–16:00, 21:00–22:00 May 13 11:00–17:00, 20:00–22:00 May 14 13:00–15:00, 20:00–22:00 May 18 11:00–16:00 May 19 13:00–16:00, 21:00–22:00 May 20 18:00–21:00 May 22 19:00–22:00 May 23 11:00–12:00, 15:00–16:00 May 25 14:00–17:00, 20:00–23:00 May 26 13:00–17:00 May 27 13:00–16:00, 21:00–23:00 May 28 13:00–16:00 May 29 12:00–16:00, 21:00–23:00 May 30 14:00–16:00 May 31 12:00–16:00
June
Jun 1 11:00–13:00 Jun 12 14:00–17:00 Jun 13 11:00–13:00, 17:00–19:00 Jun 17 14:00–17:00 Jun 23 13:00–15:00, 17:00–18:00 Jun 25 15:00–17:00, 21:00–23:00 Jun 26 13:00–16:00 Jun 27 13:00–17:00 Jun 29 13:00–15:00, 18:00–20:00 Jun 30 14:00–16:00, 20:00–21:00
July
Jul 1 12:00–16:00, 21:00–23:00 Jul 2 14:00–16:00, 21:00–23:00 Jul 3 14:00–16:00 Jul 4 14:00–18:00 Jul 6 12:00–14:00, 16:00–17:00, 20:00–23:00 Jul 7 15:00–16:00 Jul 8 14:00–17:00, 20:00–22:00 Jul 9 11:00–16:00, 22:00–23:00 Jul 10 12:00–16:00, 21:00–23:00 Jul 13 12:00–16:00, 21:00–23:00 Jul 14 13:00–16:00, 21:00–23:00 Jul 15 11:00–15:00 Jul 21 15:00–16:00, 20:00–22:00 Jul 22 11:00–13:00, 15:00–17:00, 20:00–22:00 Jul 23 13:00–14:00 Jul 24 13:00–16:00, 20:00–22:00 Jul 25 13:00–15:00 Jul 27 14:00–16:00