Most often in January, 27 days.
Highest follower count seen that year: 32,601.
January
Jan 3 14:00–24:00 Jan 4 00:00–01:00, 13:00–22:00 Jan 5 13:00–20:00 Jan 7 13:00–22:00 Jan 8 13:00–22:00 Jan 9 12:00–21:00 Jan 10 12:00–21:00 Jan 11 12:00–21:00 Jan 12 12:00–21:00 Jan 13 12:00–24:00 Jan 14 12:00–22:00 Jan 15 12:00–22:00 Jan 16 12:00–22:00 Jan 17 13:00–22:00 Jan 18 12:00–22:00 Jan 19 15:00–23:00 Jan 21 13:00–22:00 Jan 22 12:00–22:00 Jan 23 12:00–21:00 Jan 24 14:00–21:00 Jan 25 12:00–24:00 Jan 26 00:00–02:00 Jan 27 13:00–23:00 Jan 28 13:00–22:00 Jan 29 12:00–23:00 Jan 30 12:00–22:00 Jan 31 14:00–22:00
February
Feb 1 12:00–22:00 Feb 2 12:00–21:00 Feb 4 13:00–21:00 Feb 5 12:00–21:00 Feb 6 13:00–21:00 Feb 7 13:00–23:00 Feb 8 13:00–22:00 Feb 10 13:00–23:00 Feb 11 12:00–21:00 Feb 12 14:00–24:00 Feb 13 13:00–22:00 Feb 14 13:00–22:00 Feb 15 12:00–23:00 Feb 16 11:00–20:00 Feb 17 12:00–20:00 Feb 18 11:00–20:00 Feb 19 12:00–20:00 Feb 20 11:00–20:00 Feb 21 11:00–20:00 Feb 22 10:00–18:00 Feb 24 13:00–23:00 Feb 25 11:00–20:00 Feb 27 12:00–21:00 Feb 28 12:00–22:00
March
Mar 1 12:00–19:00 Mar 3 12:00–19:00 Mar 5 13:00–22:00 Mar 6 12:00–21:00 Mar 7 12:00–21:00 Mar 8 13:00–21:00 Mar 9 11:00–19:00 Mar 11 12:00–21:00 Mar 12 13:00–21:00 Mar 13 13:00–21:00 Mar 14 12:00–21:00 Mar 15 12:00–20:00 Mar 16 11:00–20:00 Mar 18 14:00–22:00 Mar 19 13:00–22:00 Mar 20 12:00–20:00 Mar 21 12:00–20:00 Mar 22 12:00–21:00 Mar 23 13:00–20:00 Mar 25 13:00–22:00 Mar 26 10:00–19:00 Mar 27 10:00–19:00 Mar 28 12:00–20:00 Mar 29 13:00–22:00 Mar 30 11:00–19:00 Mar 31 13:00–22:00
April
Apr 2 13:00–16:00 Apr 3 13:00–22:00 Apr 4 13:00–22:00 Apr 5 13:00–21:00 Apr 7 13:00–21:00 Apr 8 13:00–22:00 Apr 9 13:00–22:00 Apr 10 12:00–21:00 Apr 11 13:00–22:00 Apr 12 13:00–22:00 Apr 13 14:00–21:00 Apr 14 13:00–22:00 Apr 15 13:00–21:00 Apr 16 14:00–21:00 Apr 19 15:00–23:00 Apr 21 13:00–22:00 Apr 22 13:00–22:00 Apr 23 13:00–22:00 Apr 24 13:00–21:00 Apr 25 13:00–21:00 Apr 26 12:00–21:00 Apr 27 12:00–19:00 Apr 28 19:00–22:00 Apr 29 12:00–21:00 Apr 30 12:00–20:00
May
May 1 12:00–20:00 May 2 12:00–21:00 May 3 12:00–20:00 May 4 12:00–20:00 May 6 12:00–19:00 May 7 12:00–21:00 May 8 15:00–22:00 May 9 12:00–21:00 May 10 12:00–21:00 May 11 11:00–19:00 May 13 12:00–20:00 May 14 11:00–20:00 May 15 11:00–20:00 May 16 11:00–20:00 May 17 11:00–19:00 May 18 11:00–18:00 May 20 11:00–20:00 May 21 12:00–20:00 May 22 11:00–19:00 May 23 11:00–19:00 May 24 11:00–20:00 May 25 11:00–18:00 May 27 11:00–20:00 May 28 11:00–19:00 May 29 11:00–19:00 May 30 11:00–17:00 May 31 11:00–20:00
June
Jun 1 11:00–18:00 Jun 3 11:00–20:00 Jun 4 11:00–21:00 Jun 5 11:00–20:00 Jun 6 11:00–20:00 Jun 7 11:00–19:00 Jun 8 11:00–19:00 Jun 10 11:00–21:00 Jun 11 11:00–20:00 Jun 12 11:00–19:00 Jun 13 11:00–21:00 Jun 14 11:00–20:00 Jun 15 12:00–22:00 Jun 17 13:00–21:00 Jun 18 12:00–21:00 Jun 19 13:00–22:00 Jun 20 12:00–21:00 Jun 21 12:00–21:00 Jun 22 12:00–21:00 Jun 24 12:00–21:00 Jun 25 12:00–21:00 Jun 26 13:00–21:00 Jun 27 12:00–21:00 Jun 28 12:00–16:00
July
Jul 2 12:00–21:00 Jul 3 12:00–21:00 Jul 4 12:00–20:00 Jul 5 12:00–19:00 Jul 6 12:00–20:00 Jul 8 12:00–20:00 Jul 9 12:00–20:00 Jul 10 12:00–20:00 Jul 11 12:00–20:00 Jul 12 12:00–20:00 Jul 13 12:00–19:00 Jul 15 12:00–15:00 Jul 16 13:00–20:00 Jul 17 12:00–20:00 Jul 18 12:00–20:00 Jul 19 12:00–20:00 Jul 20 12:00–19:00 Jul 22 12:00–20:00 Jul 23 12:00–21:00 Jul 24 12:00–20:00 Jul 27 12:00–19:00 Jul 28 12:00–20:00 Jul 29 12:00–20:00 Jul 30 12:00–22:00 Jul 31 12:00–20:00
August
Aug 1 12:00–21:00 Aug 2 12:00–20:00 Aug 3 12:00–19:00 Aug 4 12:00–21:00 Aug 5 12:00–21:00 Aug 6 12:00–20:00 Aug 7 12:00–19:00 Aug 8 12:00–21:00 Aug 9 12:00–21:00 Aug 11 12:00–20:00 Aug 12 12:00–21:00 Aug 13 12:00–20:00 Aug 14 12:00–20:00 Aug 15 13:00–21:00 Aug 16 12:00–21:00 Aug 17 12:00–19:00 Aug 18 11:00–19:00 Aug 20 12:00–20:00 Aug 22 12:00–20:00 Aug 23 12:00–20:00 Aug 25 11:00–20:00 Aug 26 11:00–20:00 Aug 27 11:00–20:00 Aug 28 11:00–20:00 Aug 29 12:00–19:00 Aug 31 12:00–20:00
September
Sep 2 11:00–20:00 Sep 3 11:00–20:00 Sep 4 12:00–20:00 Sep 5 11:00–20:00 Sep 6 11:00–20:00 Sep 8 11:00–19:00 Sep 9 11:00–19:00 Sep 11 11:00–20:00 Sep 12 12:00–20:00 Sep 13 11:00–20:00 Sep 14 11:00–18:00 Sep 16 11:00–20:00 Sep 17 11:00–20:00 Sep 19 11:00–20:00 Sep 20 13:00–20:00 Sep 21 11:00–19:00 Sep 22 11:00–20:00 Sep 23 11:00–20:00 Sep 26 11:00–20:00 Sep 27 11:00–20:00 Sep 28 11:00–19:00 Sep 29 11:00–20:00 Sep 30 12:00–21:00
October
Oct 3 11:00–20:00 Oct 4 11:00–20:00 Oct 5 12:00–19:00 Oct 7 11:00–14:00 Oct 8 11:00–20:00 Oct 9 13:00–22:00 Oct 10 13:00–21:00 Oct 12 13:00–24:00 Oct 13 00:00–02:00 Oct 14 13:00–22:00 Oct 15 13:00–21:00 Oct 16 13:00–22:00 Oct 17 13:00–22:00 Oct 18 13:00–22:00 Oct 20 14:00–22:00 Oct 21 13:00–22:00 Oct 22 13:00–22:00 Oct 24 13:00–22:00 Oct 25 14:00–22:00 Oct 27 13:00–22:00 Oct 29 13:00–22:00 Oct 30 14:00–22:00 Oct 31 13:00–21:00
November
Nov 1 13:00–21:00 Nov 2 13:00–20:00 Nov 5 13:00–21:00 Nov 7 13:00–21:00 Nov 8 13:00–21:00 Nov 10 13:00–21:00 Nov 11 22:00–24:00 Nov 12 00:00–04:00, 13:00–21:00 Nov 13 13:00–21:00 Nov 14 13:00–21:00 Nov 15 13:00–21:00 Nov 17 13:00–21:00 Nov 18 13:00–21:00 Nov 19 13:00–21:00 Nov 21 13:00–19:00 Nov 22 13:00–23:00 Nov 24 13:00–22:00 Nov 25 14:00–22:00 Nov 26 13:00–22:00 Nov 27 22:00–24:00 Nov 28 00:00–04:00, 19:00–24:00 Nov 29 00:00–03:00, 17:00–24:00 Nov 30 00:00–02:00, 20:00–24:00
December
Dec 1 00:00–04:00 Dec 2 19:00–24:00 Dec 3 00:00–06:00, 19:00–24:00 Dec 5 01:00–09:00, 22:00–24:00 Dec 6 00:00–03:00 Dec 7 19:00–24:00 Dec 8 00:00–02:00 Dec 9 21:00–24:00 Dec 10 00:00–04:00, 18:00–24:00 Dec 11 00:00–02:00, 19:00–24:00 Dec 12 00:00–03:00 Dec 13 18:00–24:00 Dec 14 00:00–01:00, 17:00–24:00 Dec 15 16:00–24:00 Dec 19 23:00–24:00 Dec 20 00:00–05:00 Dec 21 13:00–22:00 Dec 23 17:00–24:00 Dec 24 00:00–01:00 Dec 25 16:00–24:00 Dec 27 16:00–23:00 Dec 29 16:00–24:00