Most often in September, 30 days.
Highest follower count seen that year: 4,739.
March
Mar 11 23:00–24:00 Mar 12 00:00–04:00, 19:00–21:00 Mar 14 23:00–24:00 Mar 15 00:00–05:00, 17:00–21:00, 23:00–24:00 Mar 16 00:00–01:00 Mar 17 21:00–24:00 Mar 18 00:00–01:00 Mar 19 00:00–05:00 Mar 20 18:00–20:00 Mar 21 21:00–24:00 Mar 22 00:00–03:00 Mar 23 02:00–05:00 Mar 24 01:00–03:00, 19:00–24:00 Mar 25 00:00–05:00, 22:00–24:00 Mar 26 00:00–02:00 Mar 27 21:00–23:00 Mar 28 00:00–04:00 Mar 31 20:00–24:00
April
Apr 1 00:00–01:00, 23:00–24:00 Apr 2 00:00–05:00 Apr 3 03:00–07:00 Apr 9 10:00–12:00 Apr 10 03:00–05:00 Apr 11 04:00–08:00 Apr 12 01:00–09:00 Apr 13 03:00–06:00 Apr 14 01:00–06:00 Apr 15 03:00–11:00 Apr 16 05:00–09:00 Apr 17 02:00–05:00 Apr 18 03:00–09:00 Apr 23 03:00–06:00 Apr 26 11:00–15:00 Apr 27 11:00–14:00
May
May 5 16:00–21:00 May 7 18:00–19:00 May 23 17:00–20:00 May 26 16:00–19:00 May 29 09:00–13:00, 15:00–17:00 May 30 11:00–14:00
June
Jun 9 17:00–22:00 Jun 10 18:00–19:00 Jun 11 18:00–20:00 Jun 14 18:00–22:00 Jun 17 10:00–19:00 Jun 18 13:00–15:00 Jun 21 19:00–21:00 Jun 27 13:00–17:00 Jun 29 13:00–20:00
July
Jul 1 18:00–21:00 Jul 2 19:00–24:00 Jul 4 13:00–21:00, 23:00–24:00 Jul 5 00:00–02:00, 11:00–17:00 Jul 7 09:00–12:00, 14:00–24:00 Jul 8 00:00–03:00 Jul 10 17:00–21:00 Jul 11 16:00–20:00 Jul 31 00:00–03:00, 22:00–24:00
August
Aug 1 00:00–01:00 Aug 4 18:00–23:00 Aug 6 17:00–21:00 Aug 7 18:00–22:00 Aug 9 00:00–03:00 Aug 12 22:00–24:00 Aug 13 23:00–24:00 Aug 14 00:00–05:00 Aug 15 01:00–05:00, 23:00–24:00 Aug 16 00:00–02:00 Aug 19 01:00–05:00, 23:00–24:00 Aug 20 00:00–03:00 Aug 21 21:00–24:00 Aug 22 00:00–02:00, 23:00–24:00 Aug 23 00:00–01:00, 22:00–24:00 Aug 24 00:00–05:00, 22:00–24:00 Aug 25 00:00–04:00, 21:00–24:00 Aug 26 00:00–04:00, 21:00–24:00 Aug 27 00:00–05:00, 21:00–24:00 Aug 28 00:00–04:00, 22:00–24:00 Aug 29 00:00–04:00, 20:00–24:00 Aug 30 00:00–02:00, 22:00–24:00 Aug 31 00:00–03:00, 19:00–24:00
September
Sep 1 00:00–05:00, 20:00–24:00 Sep 2 00:00–04:00, 21:00–24:00 Sep 3 00:00–03:00, 21:00–24:00 Sep 4 00:00–05:00, 21:00–24:00 Sep 5 00:00–06:00, 22:00–24:00 Sep 6 00:00–03:00, 22:00–24:00 Sep 7 00:00–04:00, 21:00–24:00 Sep 8 00:00–02:00, 21:00–24:00 Sep 9 00:00–03:00, 22:00–24:00 Sep 10 00:00–03:00, 21:00–24:00 Sep 11 00:00–03:00, 22:00–24:00 Sep 12 00:00–03:00, 22:00–24:00 Sep 13 00:00–06:00, 21:00–24:00 Sep 14 00:00–05:00, 22:00–24:00 Sep 15 00:00–05:00, 21:00–24:00 Sep 16 00:00–02:00, 21:00–24:00 Sep 17 00:00–04:00, 23:00–24:00 Sep 18 00:00–04:00 Sep 19 22:00–24:00 Sep 20 00:00–02:00, 22:00–24:00 Sep 21 00:00–03:00, 23:00–24:00 Sep 22 00:00–07:00, 21:00–24:00 Sep 23 00:00–02:00, 22:00–24:00 Sep 24 00:00–03:00, 22:00–24:00 Sep 25 00:00–04:00 Sep 26 00:00–03:00, 22:00–24:00 Sep 27 00:00–03:00, 22:00–24:00 Sep 28 00:00–02:00, 22:00–24:00 Sep 29 00:00–04:00, 23:00–24:00 Sep 30 00:00–04:00, 22:00–24:00
October
Oct 1 00:00–03:00, 21:00–23:00 Oct 2 22:00–24:00 Oct 3 00:00–02:00, 23:00–24:00 Oct 4 00:00–02:00 Oct 5 21:00–24:00 Oct 6 00:00–04:00, 23:00–24:00 Oct 7 00:00–04:00, 23:00–24:00 Oct 8 00:00–04:00, 22:00–24:00 Oct 9 00:00–03:00, 21:00–24:00 Oct 10 00:00–02:00, 21:00–24:00 Oct 11 00:00–03:00, 22:00–24:00 Oct 12 00:00–03:00, 23:00–24:00 Oct 13 00:00–04:00, 22:00–24:00 Oct 14 00:00–04:00 Oct 16 22:00–24:00 Oct 17 00:00–01:00, 22:00–24:00 Oct 18 00:00–02:00, 22:00–24:00 Oct 19 00:00–03:00 Oct 20 22:00–24:00 Oct 21 00:00–04:00, 22:00–24:00 Oct 22 00:00–02:00, 22:00–24:00 Oct 23 00:00–03:00, 22:00–24:00 Oct 24 00:00–03:00, 22:00–24:00 Oct 25 00:00–03:00, 23:00–24:00 Oct 26 00:00–03:00, 21:00–24:00 Oct 27 00:00–02:00, 22:00–24:00 Oct 28 00:00–02:00 Oct 29 21:00–24:00 Oct 30 00:00–04:00, 23:00–24:00 Oct 31 00:00–01:00, 21:00–24:00
November
Nov 1 00:00–03:00, 23:00–24:00 Nov 2 00:00–02:00 Nov 3 22:00–24:00 Nov 4 00:00–03:00, 22:00–24:00 Nov 5 00:00–02:00 Nov 6 23:00–24:00 Nov 7 00:00–04:00, 23:00–24:00 Nov 8 00:00–03:00, 22:00–24:00 Nov 9 00:00–03:00, 22:00–24:00 Nov 10 00:00–01:00 Nov 11 23:00–24:00 Nov 12 00:00–02:00, 21:00–24:00 Nov 13 00:00–02:00 Nov 14 23:00–24:00 Nov 15 00:00–03:00, 23:00–24:00 Nov 16 00:00–04:00 Nov 17 22:00–24:00 Nov 18 00:00–03:00, 23:00–24:00 Nov 19 00:00–03:00, 23:00–24:00 Nov 20 00:00–03:00, 23:00–24:00 Nov 21 00:00–03:00, 22:00–24:00 Nov 22 00:00–02:00 Nov 23 22:00–24:00 Nov 24 23:00–24:00 Nov 25 00:00–04:00 Nov 26 23:00–24:00 Nov 27 00:00–03:00, 21:00–24:00 Nov 28 00:00–03:00, 23:00–24:00 Nov 29 00:00–03:00 Nov 30 22:00–24:00
December
Dec 1 00:00–01:00, 22:00–24:00 Dec 2 00:00–04:00, 23:00–24:00 Dec 3 00:00–04:00, 21:00–24:00 Dec 4 00:00–03:00, 22:00–24:00 Dec 5 00:00–03:00, 23:00–24:00 Dec 6 00:00–03:00 Dec 7 00:00–04:00, 22:00–24:00 Dec 8 00:00–03:00 Dec 9 23:00–24:00 Dec 10 00:00–03:00, 22:00–24:00 Dec 11 00:00–03:00, 22:00–24:00 Dec 12 00:00–03:00, 21:00–24:00 Dec 13 00:00–03:00, 22:00–24:00 Dec 14 00:00–03:00, 23:00–24:00 Dec 15 00:00–03:00, 22:00–24:00 Dec 16 00:00–04:00, 21:00–24:00 Dec 17 00:00–03:00, 22:00–24:00 Dec 18 00:00–03:00, 22:00–24:00 Dec 19 00:00–03:00, 23:00–24:00 Dec 20 00:00–04:00, 22:00–24:00 Dec 21 00:00–03:00, 23:00–24:00 Dec 22 00:00–03:00 Dec 23 00:00–03:00, 23:00–24:00 Dec 24 00:00–04:00, 22:00–24:00 Dec 25 00:00–03:00 Dec 27 22:00–24:00 Dec 28 00:00–03:00, 22:00–24:00 Dec 29 00:00–03:00, 23:00–24:00 Dec 30 00:00–02:00