Most often in December, 27 days.
Highest follower count seen that year: 4,244.
January
Jan 1 05:00–07:00 Jan 2 09:00–10:00, 16:00–18:00 Jan 3 16:00–18:00 Jan 4 12:00–15:00 Jan 5 18:00–19:00 Jan 7 18:00–19:00 Jan 8 11:00–12:00 Jan 9 16:00–17:00 Jan 10 18:00–19:00 Jan 13 12:00–13:00 Jan 14 12:00–15:00 Jan 15 16:00–17:00 Jan 16 19:00–20:00 Jan 17 16:00–17:00 Jan 18 13:00–14:00 Jan 20 15:00–17:00 Jan 21 13:00–15:00 Jan 22 11:00–14:00, 18:00–19:00 Jan 24 19:00–20:00 Jan 25 16:00–19:00 Jan 26 12:00–13:00 Jan 27 17:00–19:00 Jan 28 12:00–14:00 Jan 29 16:00–17:00 Jan 30 18:00–20:00 Jan 31 16:00–17:00
February
Feb 1 19:00–21:00 Feb 2 17:00–19:00 Feb 4 20:00–21:00 Feb 6 16:00–17:00 Feb 8 16:00–18:00 Feb 9 16:00–18:00 Feb 10 19:00–20:00 Feb 13 14:00–15:00 Feb 15 17:00–19:00 Feb 16 19:00–20:00 Feb 18 19:00–20:00 Feb 19 17:00–19:00 Feb 20 17:00–18:00 Feb 21 18:00–19:00 Feb 22 19:00–21:00 Feb 23 19:00–20:00 Feb 25 15:00–16:00 Feb 26 18:00–19:00
March
Mar 1 14:00–16:00 Mar 3 18:00–19:00 Mar 4 12:00–14:00, 18:00–19:00 Mar 7 14:00–15:00, 18:00–20:00 Mar 8 13:00–14:00, 17:00–19:00 Mar 9 16:00–19:00 Mar 10 14:00–15:00 Mar 11 15:00–16:00 Mar 12 16:00–17:00 Mar 13 15:00–16:00 Mar 15 12:00–14:00 Mar 19 11:00–14:00, 21:00–22:00 Mar 20 09:00–10:00 Mar 21 10:00–12:00, 16:00–17:00 Mar 23 13:00–14:00 Mar 24 10:00–11:00 Mar 25 15:00–16:00 Mar 26 17:00–19:00 Mar 27 16:00–18:00 Mar 30 14:00–17:00
April
Apr 1 15:00–17:00 Apr 4 14:00–15:00 Apr 7 17:00–19:00 Apr 8 14:00–15:00 Apr 9 13:00–15:00 Apr 12 12:00–13:00, 15:00–16:00 Apr 14 11:00–13:00 Apr 16 15:00–16:00 Apr 18 15:00–17:00 Apr 20 17:00–18:00 Apr 21 17:00–18:00 Apr 23 13:00–14:00 Apr 24 15:00–17:00
May
May 1 23:00–24:00 May 2 00:00–01:00 May 4 14:00–16:00 May 7 16:00–17:00 May 8 13:00–14:00 May 9 15:00–16:00 May 10 15:00–16:00 May 11 17:00–19:00 May 13 14:00–16:00
June
Jun 8 14:00–16:00 Jun 9 16:00–18:00 Jun 12 09:00–11:00, 16:00–17:00 Jun 15 13:00–15:00 Jun 17 11:00–13:00 Jun 20 09:00–10:00 Jun 24 15:00–16:00 Jun 25 11:00–13:00 Jun 26 12:00–14:00 Jun 27 09:00–11:00 Jun 28 10:00–11:00 Jun 29 12:00–14:00 Jun 30 13:00–17:00
July
Jul 1 12:00–13:00, 16:00–17:00 Jul 2 14:00–17:00 Jul 3 20:00–22:00 Jul 4 02:00–03:00, 09:00–11:00, 17:00–19:00 Jul 5 15:00–18:00 Jul 6 17:00–20:00 Jul 7 07:00–10:00 Jul 8 10:00–12:00 Jul 9 11:00–13:00, 16:00–17:00 Jul 10 15:00–19:00 Jul 12 00:00–05:00, 10:00–12:00 Jul 13 10:00–13:00, 16:00–18:00 Jul 14 10:00–11:00 Jul 15 12:00–14:00 Jul 17 11:00–13:00 Jul 18 12:00–13:00 Jul 19 01:00–02:00 Jul 20 04:00–06:00, 09:00–12:00 Jul 21 07:00–09:00 Jul 22 05:00–06:00 Jul 26 01:00–04:00, 08:00–09:00 Jul 27 00:00–04:00, 19:00–20:00 Jul 31 08:00–10:00
August
Aug 1 02:00–04:00, 09:00–13:00 Aug 2 12:00–14:00 Aug 3 04:00–05:00, 12:00–14:00 Aug 6 06:00–08:00 Aug 8 03:00–05:00 Aug 9 04:00–05:00 Aug 14 02:00–04:00, 07:00–09:00, 21:00–22:00 Aug 19 01:00–02:00 Aug 20 12:00–14:00 Aug 23 00:00–01:00 Aug 28 00:00–02:00 Aug 29 01:00–02:00 Aug 30 10:00–11:00
September
Sep 1 08:00–10:00 Sep 3 06:00–08:00 Sep 4 09:00–10:00 Sep 5 07:00–08:00 Sep 6 00:00–01:00, 07:00–09:00, 23:00–24:00 Sep 7 04:00–06:00, 13:00–14:00 Sep 8 02:00–03:00, 10:00–11:00 Sep 9 01:00–03:00 Sep 10 02:00–03:00, 10:00–11:00 Sep 11 02:00–04:00, 09:00–10:00 Sep 12 01:00–03:00, 07:00–09:00 Sep 13 10:00–12:00, 23:00–24:00 Sep 14 02:00–04:00, 20:00–21:00 Sep 15 08:00–11:00, 18:00–20:00 Sep 17 08:00–09:00 Sep 19 10:00–11:00, 21:00–22:00 Sep 20 07:00–08:00, 18:00–19:00 Sep 21 03:00–04:00, 16:00–17:00 Sep 22 07:00–10:00, 19:00–20:00 Sep 23 00:00–01:00, 05:00–06:00 Sep 26 09:00–10:00, 21:00–22:00 Sep 27 10:00–11:00 Sep 29 04:00–05:00, 08:00–09:00
October
Oct 4 04:00–05:00 Oct 6 04:00–05:00 Oct 7 08:00–09:00, 17:00–18:00 Oct 9 08:00–09:00 Oct 10 20:00–21:00 Oct 12 03:00–04:00, 18:00–20:00 Oct 14 12:00–13:00 Oct 15 09:00–11:00, 19:00–21:00 Oct 17 21:00–22:00 Oct 18 09:00–11:00, 15:00–17:00 Oct 19 11:00–13:00 Oct 21 23:00–24:00 Oct 22 00:00–02:00 Oct 23 02:00–03:00, 21:00–22:00 Oct 25 12:00–13:00 Oct 26 14:00–15:00 Oct 28 00:00–01:00 Oct 30 10:00–12:00, 17:00–18:00
November
Nov 2 09:00–11:00 Nov 3 09:00–11:00 Nov 4 09:00–10:00 Nov 5 10:00–12:00 Nov 6 02:00–03:00, 10:00–12:00 Nov 7 12:00–14:00 Nov 8 05:00–06:00, 11:00–14:00 Nov 9 04:00–05:00 Nov 13 06:00–07:00 Nov 14 07:00–08:00 Nov 16 12:00–13:00 Nov 17 08:00–10:00 Nov 18 07:00–09:00 Nov 20 10:00–11:00 Nov 21 08:00–10:00 Nov 22 08:00–10:00 Nov 23 09:00–11:00 Nov 24 10:00–11:00 Nov 25 04:00–05:00 Nov 26 05:00–06:00 Nov 27 00:00–01:00 Nov 28 19:00–21:00 Nov 30 03:00–04:00
December
Dec 1 00:00–01:00, 12:00–13:00 Dec 4 08:00–09:00 Dec 5 02:00–03:00 Dec 6 00:00–01:00, 11:00–12:00 Dec 7 11:00–12:00, 20:00–21:00 Dec 8 10:00–11:00 Dec 9 10:00–12:00, 22:00–24:00 Dec 10 17:00–18:00 Dec 11 18:00–19:00 Dec 12 06:00–07:00, 13:00–14:00 Dec 13 01:00–02:00, 11:00–12:00 Dec 14 09:00–10:00 Dec 15 00:00–01:00 Dec 16 21:00–22:00 Dec 17 09:00–11:00, 23:00–24:00 Dec 18 03:00–04:00, 10:00–11:00 Dec 19 16:00–18:00, 22:00–23:00 Dec 20 17:00–19:00 Dec 21 03:00–04:00, 15:00–16:00 Dec 23 09:00–11:00 Dec 24 09:00–10:00 Dec 25 11:00–12:00, 17:00–19:00 Dec 26 12:00–13:00 Dec 27 02:00–03:00, 14:00–15:00 Dec 28 03:00–04:00, 18:00–19:00 Dec 30 04:00–05:00, 13:00–14:00 Dec 31 08:00–10:00