Most often in March, 23 days.
Highest follower count seen that year: 2,207.
January
Jan 1 08:00–10:00, 22:00–23:00 Jan 4 05:00–06:00 Jan 5 03:00–04:00, 14:00–15:00, 19:00–20:00 Jan 8 02:00–04:00 Jan 9 01:00–03:00 Jan 11 08:00–09:00 Jan 12 01:00–04:00, 17:00–19:00 Jan 13 03:00–04:00 Jan 14 00:00–01:00 Jan 15 01:00–03:00 Jan 18 02:00–03:00, 16:00–18:00 Jan 19 04:00–06:00, 16:00–17:00 Jan 20 01:00–03:00 Jan 21 01:00–03:00 Jan 22 01:00–03:00 Jan 23 01:00–02:00 Jan 24 02:00–03:00 Jan 25 03:00–05:00, 16:00–17:00, 21:00–22:00 Jan 26 08:00–10:00, 19:00–21:00 Jan 27 04:00–07:00, 13:00–16:00 Jan 28 03:00–05:00, 13:00–15:00 Jan 29 02:00–04:00, 12:00–14:00, 23:00–24:00 Jan 31 01:00–03:00
February
Feb 1 01:00–03:00, 14:00–16:00, 20:00–21:00 Feb 2 04:00–05:00, 16:00–18:00 Feb 4 02:00–03:00 Feb 5 02:00–04:00 Feb 6 02:00–04:00 Feb 8 02:00–04:00 Feb 9 04:00–06:00, 14:00–16:00, 19:00–21:00 Feb 11 02:00–03:00 Feb 12 01:00–03:00 Feb 13 01:00–03:00 Feb 14 02:00–03:00 Feb 15 03:00–05:00, 20:00–22:00 Feb 16 05:00–07:00, 16:00–18:00 Feb 17 01:00–03:00 Feb 18 02:00–04:00 Feb 19 01:00–02:00 Feb 21 01:00–03:00 Feb 22 04:00–06:00 Feb 23 08:00–10:00 Feb 24 03:00–04:00, 20:00–22:00 Feb 25 01:00–03:00 Feb 28 01:00–03:00
March
Mar 1 02:00–03:00 Mar 2 03:00–04:00, 14:00–16:00, 19:00–20:00 Mar 3 08:00–09:00 Mar 4 03:00–04:00, 13:00–14:00, 18:00–19:00 Mar 6 02:00–04:00 Mar 7 03:00–05:00 Mar 8 03:00–05:00, 19:00–21:00 Mar 9 02:00–05:00, 18:00–19:00 Mar 10 01:00–03:00, 14:00–16:00, 22:00–24:00 Mar 12 02:00–03:00 Mar 13 03:00–04:00 Mar 14 01:00–03:00 Mar 15 01:00–03:00 Mar 16 03:00–05:00, 15:00–18:00, 21:00–23:00 Mar 19 01:00–03:00 Mar 23 06:00–08:00, 19:00–22:00 Mar 24 02:00–05:00 Mar 25 01:00–03:00 Mar 26 12:00–13:00, 18:00–19:00 Mar 27 02:00–03:00 Mar 29 00:00–02:00 Mar 30 04:00–06:00, 15:00–17:00, 20:00–22:00 Mar 31 01:00–03:00
April
Apr 2 02:00–04:00, 15:00–17:00 Apr 4 04:00–05:00 Apr 5 02:00–04:00 Apr 6 04:00–05:00, 14:00–15:00 Apr 9 00:00–02:00 Apr 10 04:00–06:00, 11:00–12:00 Apr 11 03:00–04:00, 22:00–24:00 Apr 13 00:00–02:00, 21:00–22:00 Apr 14 01:00–03:00 Apr 16 00:00–03:00 Apr 17 05:00–06:00 Apr 18 02:00–04:00, 12:00–14:00, 21:00–23:00 Apr 19 03:00–04:00 Apr 20 15:00–16:00 Apr 24 02:00–04:00 Apr 25 02:00–04:00 Apr 26 14:00–16:00 Apr 27 01:00–03:00, 15:00–16:00 Apr 30 01:00–02:00
May
May 1 07:00–09:00, 19:00–21:00 May 2 01:00–03:00, 13:00–15:00 May 3 02:00–04:00 May 4 18:00–20:00 May 7 00:00–02:00 May 8 02:00–04:00 May 10 01:00–03:00, 14:00–16:00, 20:00–22:00 May 11 03:00–05:00, 17:00–18:00 May 12 02:00–03:00 May 14 01:00–02:00 May 15 02:00–03:00 May 16 02:00–03:00 May 17 01:00–03:00 May 18 01:00–03:00, 14:00–16:00 May 19 01:00–03:00 May 23 03:00–04:00 May 24 04:00–05:00 May 25 14:00–15:00 May 26 01:00–03:00 May 27 01:00–03:00 May 28 02:00–04:00 May 30 02:00–04:00 May 31 01:00–04:00
June
Jun 1 07:00–09:00, 23:00–24:00 Jun 2 00:00–01:00 Jun 4 00:00–02:00 Jun 7 04:00–06:00, 16:00–19:00 Jun 8 06:00–08:00, 19:00–20:00 Jun 13 02:00–05:00 Jun 15 05:00–06:00, 17:00–18:00 Jun 16 05:00–06:00, 15:00–17:00, 21:00–22:00 Jun 19 13:00–15:00, 18:00–20:00 Jun 20 20:00–22:00 Jun 21 05:00–07:00, 17:00–18:00 Jun 22 00:00–03:00, 14:00–15:00, 22:00–23:00 Jun 27 03:00–04:00 Jun 28 00:00–03:00 Jun 29 02:00–03:00 Jun 30 00:00–02:00
July
Jul 2 01:00–02:00 Jul 4 02:00–04:00 Jul 5 01:00–04:00, 14:00–17:00 Jul 6 02:00–04:00, 14:00–16:00 Jul 8 00:00–03:00 Jul 9 06:00–08:00, 20:00–22:00 Jul 10 00:00–03:00 Jul 11 01:00–03:00 Jul 12 01:00–03:00 Jul 13 01:00–03:00, 14:00–16:00 Jul 14 01:00–03:00 Jul 18 01:00–03:00 Jul 19 02:00–04:00, 14:00–16:00 Jul 23 01:00–03:00 Jul 26 01:00–03:00 Jul 27 02:00–04:00, 15:00–17:00
August
Aug 2 01:00–04:00 Aug 3 07:00–09:00, 18:00–20:00 Aug 4 02:00–04:00 Aug 7 02:00–03:00 Aug 10 02:00–04:00, 15:00–16:00 Aug 11 02:00–04:00 Aug 13 22:00–24:00 Aug 15 01:00–03:00 Aug 16 01:00–03:00 Aug 17 22:00–23:00 Aug 18 01:00–03:00 Aug 19 12:00–14:00, 22:00–24:00 Aug 20 18:00–20:00 Aug 21 13:00–15:00 Aug 22 15:00–16:00 Aug 24 13:00–15:00 Aug 28 02:00–04:00 Aug 30 05:00–06:00 Aug 31 09:00–11:00
September
Sep 7 05:00–07:00, 19:00–20:00 Sep 10 02:00–03:00 Sep 13 03:00–05:00, 14:00–16:00 Sep 14 05:00–06:00 Sep 15 02:00–04:00 Sep 21 18:00–20:00
October
Oct 5 03:00–05:00, 15:00–16:00, 20:00–21:00 Oct 20 00:00–02:00 Oct 26 02:00–03:00
November
Nov 10 19:00–21:00 Nov 11 02:00–03:00 Nov 16 02:00–05:00 Nov 17 02:00–04:00 Nov 21 16:00–18:00 Nov 22 02:00–04:00, 14:00–18:00 Nov 23 07:00–08:00, 20:00–21:00 Nov 24 03:00–05:00, 17:00–19:00 Nov 25 03:00–05:00 Nov 29 23:00–24:00 Nov 30 13:00–15:00, 21:00–22:00
December
Dec 1 02:00–03:00 Dec 5 02:00–04:00 Dec 6 07:00–09:00, 20:00–21:00 Dec 7 07:00–08:00, 19:00–20:00 Dec 8 05:00–07:00 Dec 9 00:00–02:00 Dec 10 02:00–03:00 Dec 11 02:00–03:00 Dec 14 01:00–02:00, 13:00–15:00 Dec 16 01:00–03:00 Dec 17 02:00–04:00 Dec 18 01:00–03:00 Dec 20 02:00–04:00, 20:00–21:00 Dec 21 18:00–20:00 Dec 24 05:00–09:00 Dec 27 02:00–04:00, 22:00–24:00 Dec 30 02:00–04:00, 18:00–20:00 Dec 31 02:00–04:00, 18:00–19:00