Most often in December, 26 days.
Highest follower count seen that year: 1,871.
September
Sep 6 05:00–06:00, 08:00–13:00, 23:00–24:00 Sep 7 00:00–02:00, 10:00–13:00 Sep 8 04:00–05:00, 07:00–12:00 Sep 9 07:00–10:00, 22:00–24:00 Sep 10 05:00–06:00, 08:00–09:00, 11:00–12:00 Sep 11 11:00–12:00 Sep 13 08:00–13:00 Sep 14 10:00–14:00, 22:00–24:00 Sep 15 04:00–06:00, 09:00–13:00 Sep 16 08:00–10:00 Sep 17 04:00–05:00 Sep 19 23:00–24:00 Sep 20 00:00–01:00
October
Oct 1 22:00–23:00 Oct 4 22:00–24:00 Oct 5 00:00–03:00, 08:00–12:00, 14:00–16:00, 22:00–24:00 Oct 6 00:00–01:00, 06:00–10:00 Oct 12 05:00–12:00 Oct 25 05:00–06:00, 09:00–15:00, 22:00–24:00 Oct 26 04:00–10:00 Oct 28 02:00–04:00, 23:00–24:00 Oct 29 00:00–02:00 Oct 31 22:00–24:00
November
Nov 1 00:00–01:00, 07:00–10:00, 23:00–24:00 Nov 2 01:00–03:00, 09:00–12:00, 21:00–24:00 Nov 3 00:00–01:00, 06:00–10:00, 14:00–17:00, 22:00–24:00 Nov 4 00:00–01:00, 03:00–05:00, 08:00–10:00, 15:00–16:00, 22:00–24:00 Nov 5 00:00–01:00, 03:00–11:00, 13:00–16:00, 22:00–24:00 Nov 6 00:00–01:00, 04:00–05:00, 08:00–09:00, 15:00–17:00, 23:00–24:00 Nov 7 04:00–05:00, 08:00–12:00, 23:00–24:00 Nov 8 00:00–01:00 Nov 16 04:00–06:00, 09:00–16:00, 22:00–24:00 Nov 17 00:00–01:00, 04:00–05:00, 08:00–12:00, 22:00–24:00 Nov 18 00:00–01:00, 03:00–05:00, 08:00–12:00, 22:00–24:00 Nov 19 00:00–01:00, 04:00–06:00, 08:00–11:00, 22:00–24:00 Nov 20 00:00–01:00, 04:00–10:00, 23:00–24:00 Nov 21 00:00–02:00, 04:00–06:00, 08:00–14:00, 22:00–24:00 Nov 22 00:00–01:00, 05:00–06:00, 08:00–12:00, 14:00–15:00, 23:00–24:00 Nov 23 09:00–17:00, 23:00–24:00 Nov 24 00:00–01:00, 04:00–06:00, 08:00–11:00, 14:00–17:00 Nov 25 03:00–05:00, 08:00–12:00, 15:00–17:00, 22:00–24:00 Nov 26 00:00–01:00, 04:00–06:00, 08:00–12:00, 14:00–17:00, 23:00–24:00 Nov 27 00:00–01:00, 04:00–06:00, 10:00–12:00, 14:00–16:00 Nov 28 04:00–07:00, 10:00–11:00, 15:00–16:00, 23:00–24:00 Nov 29 00:00–01:00, 08:00–11:00, 15:00–17:00, 22:00–24:00 Nov 30 00:00–01:00, 05:00–06:00, 08:00–09:00, 15:00–16:00, 22:00–24:00
December
Dec 1 00:00–01:00, 03:00–04:00, 08:00–09:00, 15:00–16:00, 22:00–24:00 Dec 2 03:00–11:00, 13:00–14:00, 23:00–24:00 Dec 3 00:00–01:00, 03:00–05:00, 07:00–11:00, 14:00–15:00, 22:00–23:00 Dec 4 00:00–01:00, 04:00–06:00, 08:00–12:00, 14:00–16:00, 22:00–24:00 Dec 5 03:00–05:00, 07:00–12:00, 15:00–16:00, 23:00–24:00 Dec 6 04:00–05:00, 08:00–10:00, 14:00–15:00, 23:00–24:00 Dec 7 01:00–02:00, 07:00–11:00, 14:00–16:00, 22:00–24:00 Dec 8 03:00–04:00, 07:00–08:00, 14:00–15:00 Dec 9 08:00–09:00, 23:00–24:00 Dec 10 08:00–12:00, 14:00–16:00, 23:00–24:00 Dec 11 03:00–04:00, 08:00–12:00, 23:00–24:00 Dec 12 03:00–13:00, 15:00–17:00, 22:00–23:00 Dec 13 00:00–01:00, 03:00–16:00, 22:00–24:00 Dec 14 00:00–01:00, 03:00–05:00, 07:00–11:00, 14:00–16:00, 22:00–24:00 Dec 15 00:00–01:00, 03:00–11:00, 14:00–16:00, 22:00–23:00 Dec 16 03:00–06:00, 09:00–12:00, 15:00–16:00, 23:00–24:00 Dec 17 00:00–01:00, 03:00–06:00, 08:00–10:00 Dec 18 00:00–01:00, 08:00–09:00, 11:00–12:00, 23:00–24:00 Dec 19 03:00–05:00 Dec 20 04:00–12:00, 14:00–15:00, 22:00–23:00 Dec 21 04:00–11:00, 13:00–14:00, 22:00–23:00 Dec 22 14:00–16:00, 22:00–24:00 Dec 23 00:00–01:00, 04:00–05:00 Dec 24 08:00–12:00, 22:00–24:00 Dec 25 00:00–01:00, 03:00–05:00, 07:00–12:00, 14:00–16:00 Dec 26 00:00–01:00, 08:00–13:00, 15:00–17:00, 22:00–23:00