Most often in December, 30 days.
Highest follower count seen that year: 3,157.
April
Apr 25 00:00–07:00, 14:00–18:00, 20:00–22:00 Apr 26 13:00–17:00, 23:00–24:00 Apr 27 00:00–03:00, 13:00–19:00, 23:00–24:00 Apr 28 00:00–01:00, 22:00–24:00 Apr 29 00:00–07:00, 16:00–24:00 Apr 30 01:00–06:00, 10:00–12:00, 18:00–21:00
May
May 1 00:00–04:00, 07:00–10:00, 13:00–16:00 May 3 14:00–17:00 May 4 04:00–05:00, 15:00–22:00 May 5 05:00–09:00, 11:00–14:00, 16:00–17:00 May 7 16:00–22:00 May 8 11:00–16:00 May 9 14:00–16:00 May 10 18:00–21:00 May 11 12:00–19:00 May 12 13:00–14:00 May 14 10:00–16:00 May 15 13:00–22:00 May 16 00:00–02:00, 14:00–23:00 May 17 14:00–17:00, 23:00–24:00 May 18 00:00–02:00, 23:00–24:00 May 19 00:00–01:00, 12:00–16:00, 23:00–24:00 May 20 00:00–03:00, 23:00–24:00 May 21 00:00–01:00, 12:00–17:00 May 22 02:00–03:00, 12:00–14:00 May 23 02:00–03:00, 13:00–17:00, 21:00–24:00 May 24 00:00–02:00, 12:00–17:00 May 25 01:00–03:00, 12:00–17:00 May 26 00:00–01:00 May 27 08:00–16:00 May 28 08:00–10:00, 12:00–16:00 May 29 13:00–21:00 May 30 12:00–23:00 May 31 00:00–06:00, 13:00–15:00, 23:00–24:00
June
Jun 1 00:00–02:00, 12:00–21:00 Jun 2 07:00–11:00, 14:00–17:00 Jun 3 21:00–24:00 Jun 10 16:00–21:00 Jun 11 11:00–22:00 Jun 12 09:00–22:00 Jun 15 11:00–16:00 Jun 16 13:00–19:00 Jun 17 10:00–19:00 Jun 18 13:00–19:00 Jun 19 12:00–24:00 Jun 20 18:00–22:00 Jun 21 11:00–14:00 Jun 22 18:00–21:00 Jun 23 12:00–16:00 Jun 24 00:00–01:00, 12:00–22:00 Jun 25 17:00–22:00 Jun 26 09:00–10:00, 15:00–17:00 Jun 27 15:00–17:00, 21:00–23:00 Jun 29 10:00–14:00, 17:00–19:00 Jun 30 11:00–12:00, 16:00–19:00
July
Jul 1 07:00–11:00, 15:00–18:00 Jul 3 11:00–20:00 Jul 4 04:00–05:00, 08:00–10:00, 12:00–13:00, 16:00–17:00 Jul 12 07:00–15:00 Jul 13 10:00–15:00 Jul 17 09:00–19:00 Jul 18 10:00–17:00 Jul 19 11:00–16:00 Jul 20 10:00–18:00 Jul 21 10:00–19:00 Jul 30 10:00–17:00
August
Aug 17 08:00–16:00 Aug 19 12:00–14:00, 16:00–19:00 Aug 20 06:00–16:00 Aug 23 11:00–19:00 Aug 24 08:00–15:00
September
Sep 4 16:00–18:00 Sep 5 14:00–17:00 Sep 6 21:00–24:00 Sep 7 12:00–13:00, 16:00–17:00 Sep 8 23:00–24:00 Sep 9 00:00–03:00 Sep 11 20:00–22:00 Sep 14 16:00–19:00 Sep 15 19:00–21:00 Sep 17 00:00–02:00, 14:00–24:00 Sep 18 00:00–01:00 Sep 19 17:00–24:00 Sep 20 02:00–03:00, 13:00–19:00 Sep 21 14:00–20:00 Sep 30 16:00–24:00
October
Oct 3 19:00–24:00 Oct 4 00:00–02:00, 20:00–24:00 Oct 5 01:00–03:00, 17:00–23:00 Oct 8 17:00–24:00 Oct 9 00:00–04:00, 21:00–24:00 Oct 10 00:00–05:00 Oct 12 01:00–05:00, 20:00–24:00 Oct 13 00:00–04:00, 21:00–24:00 Oct 14 00:00–06:00, 08:00–09:00 Oct 15 00:00–20:00 Oct 16 05:00–18:00 Oct 17 08:00–18:00 Oct 18 06:00–16:00 Oct 19 07:00–09:00 Oct 20 18:00–21:00 Oct 21 09:00–20:00 Oct 22 08:00–21:00 Oct 23 07:00–20:00 Oct 24 08:00–19:00 Oct 25 13:00–21:00 Oct 26 14:00–22:00 Oct 27 10:00–21:00 Oct 28 10:00–21:00 Oct 29 13:00–24:00 Oct 30 00:00–01:00, 16:00–24:00 Oct 31 00:00–05:00, 17:00–24:00
November
Nov 1 00:00–05:00 Nov 2 16:00–24:00 Nov 3 00:00–03:00 Nov 5 09:00–17:00 Nov 6 13:00–22:00 Nov 7 18:00–24:00 Nov 8 00:00–02:00, 17:00–24:00 Nov 9 00:00–01:00 Nov 10 18:00–24:00 Nov 11 00:00–04:00, 10:00–23:00 Nov 12 14:00–15:00 Nov 18 07:00–19:00 Nov 19 13:00–20:00 Nov 21 01:00–03:00, 18:00–24:00 Nov 22 00:00–01:00, 16:00–24:00 Nov 23 00:00–03:00 Nov 24 01:00–04:00, 18:00–20:00, 22:00–23:00 Nov 26 18:00–24:00 Nov 27 00:00–02:00, 19:00–24:00 Nov 28 00:00–04:00, 21:00–24:00 Nov 29 00:00–02:00, 04:00–06:00 Nov 30 00:00–07:00, 17:00–21:00
December
Dec 1 10:00–15:00, 19:00–23:00 Dec 2 08:00–18:00 Dec 3 06:00–17:00 Dec 4 06:00–18:00 Dec 5 06:00–17:00 Dec 6 16:00–24:00 Dec 7 00:00–01:00, 10:00–18:00 Dec 8 07:00–23:00 Dec 9 06:00–18:00 Dec 10 02:00–19:00 Dec 11 05:00–21:00 Dec 12 05:00–17:00 Dec 13 05:00–06:00, 08:00–14:00 Dec 14 07:00–18:00 Dec 15 08:00–17:00 Dec 16 08:00–17:00 Dec 17 11:00–15:00 Dec 19 11:00–19:00 Dec 20 16:00–21:00, 23:00–24:00 Dec 21 00:00–03:00, 15:00–19:00 Dec 22 18:00–24:00 Dec 23 00:00–01:00 Dec 24 15:00–24:00 Dec 25 00:00–06:00, 14:00–24:00 Dec 26 00:00–01:00, 14:00–23:00 Dec 27 16:00–24:00 Dec 28 18:00–24:00 Dec 29 02:00–07:00, 22:00–24:00 Dec 30 00:00–06:00, 20:00–24:00 Dec 31 00:00–04:00, 17:00–22:00