Most often in April, 29 days.
Highest follower count seen that year: 2,365.
January
Jan 1 04:00–05:00, 07:00–08:00
March
Mar 15 22:00–23:00 Mar 16 23:00–24:00 Mar 17 00:00–01:00, 08:00–10:00 Mar 18 01:00–03:00, 08:00–09:00 Mar 19 08:00–10:00, 18:00–19:00 Mar 20 10:00–11:00, 15:00–17:00 Mar 21 02:00–03:00, 16:00–19:00 Mar 22 12:00–15:00, 20:00–21:00 Mar 23 02:00–03:00, 13:00–15:00 Mar 24 02:00–03:00 Mar 25 12:00–15:00, 19:00–20:00, 23:00–24:00 Mar 26 00:00–01:00, 05:00–06:00, 12:00–13:00, 16:00–17:00 Mar 27 05:00–06:00, 16:00–17:00, 22:00–23:00 Mar 28 07:00–10:00, 16:00–19:00, 22:00–23:00 Mar 29 17:00–23:00 Mar 30 05:00–06:00, 08:00–09:00, 14:00–17:00, 22:00–23:00 Mar 31 07:00–08:00, 22:00–24:00
April
Apr 1 09:00–10:00, 14:00–15:00, 20:00–21:00 Apr 2 10:00–12:00 Apr 3 00:00–01:00, 03:00–04:00, 09:00–10:00 Apr 4 06:00–09:00, 12:00–13:00 Apr 5 12:00–13:00, 16:00–17:00 Apr 6 06:00–07:00, 10:00–11:00 Apr 7 13:00–15:00 Apr 8 04:00–08:00, 12:00–14:00, 17:00–18:00, 23:00–24:00 Apr 9 07:00–09:00 Apr 10 02:00–03:00, 07:00–08:00, 19:00–20:00 Apr 11 18:00–19:00 Apr 13 00:00–01:00, 04:00–05:00, 10:00–11:00, 14:00–15:00, 18:00–20:00 Apr 14 02:00–04:00, 18:00–19:00 Apr 15 01:00–02:00, 09:00–10:00 Apr 16 06:00–08:00, 11:00–12:00, 17:00–18:00 Apr 17 16:00–17:00, 22:00–23:00 Apr 18 07:00–08:00, 12:00–13:00, 17:00–19:00 Apr 19 06:00–09:00, 13:00–14:00, 17:00–20:00, 22:00–23:00 Apr 20 11:00–15:00 Apr 21 03:00–04:00, 07:00–08:00, 11:00–16:00, 21:00–22:00 Apr 22 12:00–14:00, 17:00–18:00 Apr 23 01:00–02:00, 05:00–06:00, 19:00–20:00 Apr 24 03:00–04:00, 08:00–11:00, 20:00–24:00 Apr 25 07:00–09:00, 18:00–19:00 Apr 26 02:00–04:00, 11:00–12:00, 20:00–21:00 Apr 27 16:00–17:00, 20:00–21:00 Apr 28 08:00–09:00, 17:00–19:00, 22:00–24:00 Apr 29 04:00–05:00, 09:00–10:00 Apr 30 02:00–04:00, 09:00–10:00, 19:00–21:00
May
May 1 06:00–09:00, 12:00–16:00 May 3 01:00–02:00, 04:00–07:00, 15:00–17:00 May 5 00:00–04:00, 08:00–09:00, 21:00–22:00 May 7 00:00–01:00, 06:00–07:00, 09:00–10:00, 15:00–16:00 May 8 06:00–07:00, 12:00–13:00, 23:00–24:00 May 9 14:00–16:00 May 10 12:00–13:00, 18:00–19:00 May 11 00:00–01:00, 16:00–17:00 May 12 05:00–07:00, 09:00–11:00, 15:00–16:00, 22:00–23:00 May 13 03:00–04:00, 08:00–09:00 May 14 16:00–17:00 May 15 20:00–21:00 May 16 04:00–05:00, 12:00–13:00 May 17 06:00–09:00, 18:00–19:00, 21:00–22:00 May 18 04:00–06:00, 09:00–10:00, 20:00–21:00 May 19 00:00–01:00, 09:00–11:00 May 20 00:00–02:00, 05:00–06:00, 08:00–09:00 May 21 09:00–12:00, 18:00–20:00 May 22 15:00–18:00 May 23 00:00–01:00, 10:00–11:00 May 24 00:00–01:00, 14:00–15:00, 23:00–24:00 May 25 10:00–11:00, 14:00–15:00, 20:00–21:00 May 27 00:00–07:00, 15:00–16:00, 20:00–21:00 May 28 04:00–05:00, 21:00–22:00 May 29 01:00–03:00, 06:00–07:00, 11:00–13:00, 15:00–19:00 May 30 08:00–10:00, 15:00–17:00 May 31 18:00–20:00, 22:00–23:00
June
Jun 1 01:00–02:00, 14:00–17:00, 21:00–24:00 Jun 2 00:00–01:00, 23:00–24:00 Jun 3 07:00–08:00, 11:00–13:00 Jun 4 02:00–03:00, 09:00–10:00, 15:00–20:00, 23:00–24:00 Jun 5 00:00–01:00, 08:00–09:00, 14:00–15:00, 23:00–24:00 Jun 6 08:00–10:00 Jun 7 02:00–04:00, 14:00–15:00 Jun 8 02:00–05:00, 09:00–10:00, 17:00–18:00, 23:00–24:00 Jun 9 00:00–01:00, 05:00–07:00, 12:00–19:00 Jun 10 01:00–03:00, 14:00–15:00, 23:00–24:00 Jun 11 08:00–10:00, 23:00–24:00 Jun 12 06:00–07:00, 13:00–14:00, 16:00–17:00, 19:00–23:00 Jun 13 08:00–09:00, 18:00–19:00 Jun 15 10:00–12:00, 15:00–16:00, 22:00–24:00 Jun 16 02:00–03:00, 08:00–10:00, 12:00–13:00, 21:00–24:00 Jun 17 04:00–09:00, 19:00–20:00 Jun 19 11:00–13:00, 22:00–23:00 Jun 20 22:00–24:00 Jun 21 08:00–09:00, 17:00–19:00, 23:00–24:00 Jun 22 06:00–09:00, 18:00–20:00 Jun 23 06:00–07:00, 17:00–18:00, 20:00–21:00 Jun 24 08:00–09:00, 21:00–22:00 Jun 25 05:00–06:00, 18:00–20:00 Jun 26 03:00–04:00, 17:00–18:00 Jun 27 05:00–06:00, 22:00–23:00 Jun 28 20:00–21:00 Jun 29 04:00–06:00, 14:00–15:00, 17:00–19:00, 21:00–22:00 Jun 30 10:00–11:00, 20:00–23:00
July
Jul 1 21:00–24:00 Jul 2 07:00–10:00 Jul 3 15:00–19:00 Jul 4 00:00–01:00, 07:00–09:00, 20:00–22:00 Jul 5 03:00–04:00, 11:00–12:00, 14:00–15:00, 17:00–20:00, 23:00–24:00 Jul 6 12:00–13:00, 20:00–24:00 Jul 7 01:00–02:00, 21:00–22:00 Jul 8 01:00–03:00, 07:00–10:00, 12:00–17:00, 19:00–20:00 Jul 9 00:00–01:00, 11:00–12:00 Jul 10 00:00–01:00, 10:00–11:00, 16:00–19:00, 22:00–24:00 Jul 11 03:00–04:00, 10:00–11:00, 23:00–24:00 Jul 12 06:00–08:00, 13:00–17:00 Jul 13 04:00–05:00, 11:00–12:00, 17:00–18:00, 23:00–24:00 Jul 14 00:00–02:00, 06:00–08:00 Jul 15 01:00–03:00, 16:00–18:00, 20:00–23:00 Jul 16 01:00–02:00, 09:00–14:00 Jul 17 05:00–07:00, 10:00–12:00, 19:00–20:00 Jul 18 08:00–09:00, 12:00–13:00, 15:00–16:00 Jul 19 20:00–22:00 Jul 20 04:00–05:00, 09:00–10:00, 17:00–21:00 Jul 21 01:00–02:00, 10:00–11:00, 16:00–18:00 Jul 22 07:00–08:00 Jul 23 04:00–05:00, 19:00–20:00 Jul 24 00:00–03:00, 10:00–11:00, 19:00–20:00 Jul 25 19:00–21:00 Jul 26 08:00–09:00, 11:00–12:00, 15:00–17:00, 21:00–22:00