Most often in October, 21 days.
Highest follower count seen that year: 81,248.
January
Jan 6 02:00–08:00 Jan 7 02:00–07:00 Jan 8 02:00–08:00 Jan 9 02:00–08:00 Jan 10 02:00–08:00 Jan 12 02:00–08:00 Jan 13 02:00–08:00 Jan 15 03:00–09:00 Jan 16 02:00–09:00 Jan 17 02:00–08:00 Jan 19 02:00–08:00 Jan 20 02:00–09:00 Jan 22 02:00–08:00 Jan 23 02:00–08:00 Jan 24 02:00–08:00 Jan 26 02:00–08:00 Jan 27 02:00–09:00 Jan 29 02:00–09:00 Jan 30 02:00–08:00 Jan 31 02:00–09:00
February
Feb 2 02:00–08:00 Feb 3 02:00–08:00 Feb 5 02:00–08:00 Feb 6 02:00–08:00 Feb 7 02:00–09:00 Feb 9 02:00–08:00 Feb 10 02:00–08:00 Feb 12 02:00–08:00 Feb 13 02:00–08:00 Feb 14 02:00–08:00 Feb 16 02:00–08:00 Feb 17 02:00–08:00 Feb 19 02:00–08:00 Feb 21 02:00–08:00 Feb 23 02:00–08:00 Feb 24 02:00–07:00 Feb 26 02:00–09:00 Feb 27 02:00–09:00 Feb 28 02:00–08:00
March
Mar 5 02:00–08:00 Mar 6 02:00–09:00 Mar 9 02:00–09:00 Mar 10 02:00–08:00 Mar 11 02:00–08:00 Mar 13 03:00–08:00 Mar 14 02:00–08:00 Mar 15 02:00–08:00 Mar 17 02:00–08:00 Mar 18 02:00–09:00 Mar 20 02:00–09:00 Mar 21 02:00–08:00 Mar 23 02:00–08:00 Mar 24 02:00–08:00 Mar 26 02:00–08:00 Mar 27 02:00–08:00 Mar 28 02:00–08:00 Mar 30 02:00–08:00 Mar 31 02:00–08:00
April
Apr 2 02:00–09:00 Apr 3 02:00–08:00 Apr 4 02:00–08:00 Apr 6 02:00–08:00 Apr 7 02:00–08:00 Apr 9 02:00–08:00 Apr 10 02:00–08:00 Apr 11 02:00–08:00 Apr 13 02:00–09:00 Apr 15 02:00–09:00 Apr 16 02:00–08:00 Apr 17 02:00–08:00 Apr 18 02:00–08:00 Apr 21 02:00–08:00 Apr 23 03:00–08:00 Apr 24 02:00–08:00 Apr 25 02:00–08:00 Apr 27 02:00–09:00 Apr 28 02:00–08:00 Apr 29 02:00–08:00 Apr 30 02:00–08:00
May
May 5 04:00–08:00 May 6 02:00–09:00 May 7 02:00–09:00 May 8 02:00–09:00 May 10 02:00–09:00 May 11 02:00–08:00 May 12 02:00–08:00 May 14 02:00–08:00 May 15 02:00–08:00 May 16 02:00–08:00 May 18 02:00–08:00 May 19 02:00–08:00 May 21 03:00–09:00 May 22 02:00–08:00 May 23 02:00–08:00 May 25 02:00–09:00 May 26 02:00–09:00 May 28 02:00–08:00 May 29 02:00–09:00 May 30 02:00–09:00 May 31 02:00–08:00
June
Jun 2 02:00–08:00 Jun 4 02:00–09:00 Jun 5 02:00–09:00 Jun 6 02:00–08:00 Jun 10 02:00–09:00 Jun 11 02:00–09:00 Jun 12 02:00–09:00 Jun 14 02:00–09:00 Jun 15 02:00–09:00 Jun 16 02:00–09:00 Jun 18 02:00–09:00 Jun 19 02:00–08:00 Jun 20 03:00–08:00 Jun 22 02:00–09:00 Jun 23 02:00–09:00 Jun 25 02:00–09:00 Jun 26 02:00–08:00 Jun 27 02:00–08:00 Jun 29 02:00–09:00 Jun 30 02:00–09:00
July
Jul 2 12:00–19:00 Jul 3 12:00–18:00 Jul 4 12:00–18:00 Jul 6 12:00–18:00 Jul 7 12:00–18:00 Jul 9 12:00–19:00 Jul 10 12:00–19:00 Jul 11 12:00–18:00 Jul 13 12:00–18:00 Jul 14 12:00–19:00 Jul 16 12:00–19:00 Jul 17 12:00–19:00 Jul 18 12:00–18:00 Jul 20 12:00–21:00 Jul 21 13:00–21:00 Jul 23 12:00–20:00 Jul 25 12:00–21:00 Jul 27 13:00–21:00
August
Aug 4 12:00–21:00 Aug 6 12:00–21:00 Aug 8 13:00–19:00 Aug 10 13:00–22:00 Aug 11 12:00–20:00 Aug 12 13:00–21:00 Aug 14 13:00–20:00 Aug 15 12:00–21:00
September
Sep 1 16:00–22:00 Sep 2 13:00–22:00 Sep 4 14:00–21:00 Sep 5 14:00–22:00 Sep 10 13:00–21:00 Sep 11 13:00–22:00 Sep 13 16:00–24:00 Sep 14 16:00–24:00 Sep 15 16:00–24:00 Sep 17 16:00–24:00 Sep 18 17:00–23:00 Sep 20 16:00–24:00 Sep 21 16:00–22:00 Sep 24 16:00–24:00 Sep 25 16:00–23:00 Sep 27 17:00–23:00 Sep 28 16:00–24:00 Sep 29 17:00–23:00
October
Oct 1 16:00–22:00 Oct 2 16:00–24:00 Oct 4 05:00–11:00 Oct 6 16:00–23:00 Oct 8 16:00–23:00 Oct 9 16:00–22:00 Oct 11 05:00–11:00 Oct 13 05:00–10:00 Oct 14 16:00–23:00 Oct 17 16:00–23:00 Oct 18 16:00–23:00 Oct 19 16:00–22:00 Oct 20 16:00–22:00 Oct 22 16:00–23:00 Oct 23 16:00–22:00 Oct 24 16:00–21:00 Oct 26 17:00–23:00 Oct 27 16:00–22:00 Oct 29 16:00–23:00 Oct 30 16:00–23:00 Oct 31 17:00–23:00
November
Nov 5 16:00–23:00 Nov 6 16:00–22:00 Nov 7 16:00–22:00 Nov 8 17:00–23:00 Nov 9 16:00–23:00 Nov 10 17:00–20:00 Nov 12 16:00–22:00 Nov 13 16:00–20:00 Nov 15 16:00–23:00 Nov 16 16:00–23:00 Nov 17 01:00–06:00 Nov 19 16:00–22:00 Nov 20 16:00–23:00 Nov 23 17:00–22:00 Nov 24 16:00–22:00 Nov 25 01:00–05:00 Nov 26 17:00–23:00 Nov 27 16:00–21:00 Nov 29 16:00–21:00 Nov 30 16:00–22:00
December
Dec 2 16:00–19:00 Dec 4 16:00–22:00 Dec 5 16:00–22:00 Dec 7 16:00–22:00 Dec 8 16:00–22:00 Dec 9 16:00–22:00 Dec 10 01:00–07:00 Dec 12 17:00–22:00 Dec 13 16:00–22:00 Dec 14 16:00–24:00 Dec 16 17:00–23:00 Dec 18 17:00–22:00 Dec 23 17:00–22:00 Dec 24 16:00–22:00 Dec 26 16:00–21:00 Dec 28 03:00–08:00