Most often in January, 24 days.
Highest follower count seen that year: 71,899.
January
Jan 2 20:00–23:00 Jan 3 12:00–15:00 Jan 4 13:00–16:00 Jan 6 18:00–21:00 Jan 7 13:00–16:00, 21:00–23:00 Jan 8 20:00–21:00 Jan 9 14:00–17:00 Jan 10 11:00–14:00 Jan 11 14:00–18:00 Jan 12 16:00–18:00 Jan 13 15:00–17:00 Jan 14 17:00–21:00 Jan 15 20:00–22:00 Jan 16 17:00–20:00 Jan 18 15:00–18:00 Jan 20 21:00–23:00 Jan 21 21:00–23:00 Jan 22 20:00–22:00 Jan 23 20:00–22:00 Jan 26 22:00–24:00 Jan 27 00:00–03:00 Jan 28 20:00–24:00 Jan 29 14:00–19:00, 22:00–24:00 Jan 30 11:00–16:00, 21:00–23:00
February
Feb 2 21:00–24:00 Feb 3 20:00–24:00 Feb 4 18:00–24:00 Feb 5 10:00–12:00 Feb 6 16:00–20:00 Feb 7 14:00–18:00 Feb 10 20:00–24:00 Feb 11 20:00–24:00 Feb 12 20:00–23:00 Feb 13 20:00–22:00 Feb 14 19:00–22:00 Feb 17 20:00–23:00 Feb 21 14:00–17:00 Feb 23 18:00–20:00 Feb 24 15:00–19:00 Feb 26 19:00–22:00 Feb 28 17:00–19:00
March
Mar 1 19:00–22:00 Mar 2 18:00–20:00 Mar 3 18:00–20:00 Mar 4 18:00–22:00 Mar 5 14:00–23:00 Mar 6 19:00–24:00 Mar 7 16:00–17:00 Mar 10 14:00–19:00, 22:00–23:00 Mar 11 18:00–20:00 Mar 12 15:00–18:00 Mar 13 15:00–19:00 Mar 14 15:00–17:00 Mar 16 15:00–17:00 Mar 17 15:00–20:00 Mar 18 15:00–18:00 Mar 19 16:00–20:00 Mar 20 08:00–13:00 Mar 23 12:00–16:00 Mar 26 18:00–21:00 Mar 27 16:00–20:00, 23:00–24:00 Mar 28 00:00–01:00, 15:00–17:00 Mar 31 13:00–14:00, 21:00–23:00
April
Apr 1 15:00–21:00, 23:00–24:00 Apr 2 11:00–16:00 Apr 3 18:00–22:00 Apr 4 13:00–15:00 Apr 7 18:00–21:00 Apr 8 07:00–11:00, 14:00–18:00 Apr 9 15:00–18:00 Apr 11 18:00–20:00 Apr 13 13:00–15:00 Apr 14 21:00–23:00 Apr 15 13:00–14:00, 23:00–24:00 Apr 16 22:00–24:00 Apr 17 00:00–01:00, 21:00–24:00 Apr 18 00:00–01:00 Apr 22 21:00–23:00 Apr 23 21:00–24:00 Apr 24 00:00–01:00, 20:00–23:00 Apr 28 20:00–23:00 Apr 30 21:00–24:00
May
May 1 20:00–23:00 May 2 16:00–18:00 May 3 21:00–23:00 May 4 18:00–22:00 May 5 22:00–24:00 May 6 00:00–01:00, 19:00–23:00 May 7 13:00–16:00, 19:00–22:00 May 8 13:00–15:00, 19:00–21:00 May 12 19:00–21:00 May 13 13:00–15:00 May 14 13:00–16:00, 18:00–21:00 May 16 19:00–23:00 May 18 18:00–23:00 May 19 18:00–21:00 May 20 19:00–24:00 May 21 10:00–13:00 May 22 13:00–14:00, 21:00–23:00 May 23 12:00–14:00, 19:00–23:00 May 26 19:00–23:00 May 27 21:00–23:00 May 29 20:00–24:00 May 30 00:00–01:00, 22:00–24:00 May 31 00:00–01:00
June
Jun 2 13:00–15:00, 19:00–22:00 Jun 3 13:00–15:00, 19:00–24:00 Jun 4 13:00–16:00, 19:00–23:00 Jun 5 14:00–17:00 Jun 8 20:00–24:00 Jun 9 00:00–02:00, 20:00–24:00 Jun 10 00:00–01:00, 15:00–19:00 Jun 11 19:00–23:00 Jun 12 13:00–16:00, 20:00–24:00 Jun 16 19:00–24:00 Jun 17 00:00–01:00 Jun 18 13:00–14:00, 20:00–23:00 Jun 19 16:00–23:00 Jun 20 13:00–16:00 Jun 23 14:00–15:00, 20:00–24:00 Jun 24 13:00–16:00 Jun 25 12:00–15:00 Jun 26 13:00–15:00 Jun 27 13:00–15:00 Jun 30 14:00–16:00
July
Jul 1 13:00–17:00 Jul 2 12:00–14:00, 21:00–24:00 Jul 3 14:00–17:00 Jul 4 13:00–15:00 Jul 8 12:00–15:00 Jul 9 12:00–15:00, 21:00–24:00 Jul 10 13:00–16:00, 22:00–24:00 Jul 14 13:00–16:00 Jul 15 12:00–15:00, 21:00–24:00 Jul 16 13:00–16:00 Jul 17 14:00–17:00 Jul 22 14:00–17:00 Jul 23 14:00–17:00 Jul 24 13:00–17:00 Jul 25 12:00–15:00 Jul 28 19:00–22:00 Jul 30 17:00–19:00 Jul 31 15:00–18:00
August
Aug 1 14:00–17:00 Aug 4 21:00–23:00 Aug 5 14:00–15:00, 21:00–23:00 Aug 6 13:00–14:00 Aug 8 12:00–16:00, 22:00–23:00 Aug 11 22:00–24:00 Aug 13 13:00–14:00, 20:00–23:00 Aug 17 21:00–23:00 Aug 19 13:00–16:00 Aug 20 16:00–19:00 Aug 21 16:00–18:00, 21:00–24:00 Aug 22 12:00–15:00, 22:00–24:00 Aug 23 12:00–15:00 Aug 25 19:00–22:00 Aug 26 14:00–15:00 Aug 28 16:00–19:00, 21:00–23:00
September
Sep 1 21:00–23:00 Sep 2 17:00–20:00 Sep 3 21:00–22:00 Sep 4 17:00–18:00 Sep 5 14:00–17:00 Sep 8 17:00–18:00, 21:00–23:00 Sep 9 13:00–15:00, 19:00–23:00 Sep 10 17:00–19:00, 21:00–23:00 Sep 11 13:00–16:00 Sep 12 12:00–16:00 Sep 14 21:00–24:00 Sep 15 08:00–09:00, 14:00–16:00 Sep 16 14:00–23:00 Sep 18 13:00–17:00, 21:00–24:00 Sep 19 16:00–18:00, 21:00–24:00 Sep 20 00:00–01:00 Sep 22 19:00–22:00 Sep 23 16:00–18:00, 20:00–23:00 Sep 24 20:00–23:00 Sep 26 13:00–15:00 Sep 29 20:00–24:00 Sep 30 19:00–23:00
October
Oct 1 13:00–15:00, 20:00–23:00 Oct 7 13:00–17:00 Oct 8 20:00–24:00 Oct 9 15:00–17:00, 22:00–24:00 Oct 10 00:00–01:00 Oct 13 14:00–16:00 Oct 14 15:00–20:00 Oct 19 13:00–17:00 Oct 24 13:00–18:00 Oct 25 17:00–21:00 Oct 26 17:00–18:00 Oct 27 14:00–17:00 Oct 28 21:00–23:00 Oct 30 22:00–24:00
November
Nov 3 23:00–24:00 Nov 4 00:00–01:00, 18:00–19:00, 22:00–24:00 Nov 5 00:00–01:00, 17:00–20:00 Nov 6 16:00–20:00, 23:00–24:00 Nov 7 00:00–01:00 Nov 12 14:00–17:00, 22:00–24:00 Nov 13 00:00–01:00, 14:00–19:00 Nov 14 16:00–18:00 Nov 18 22:00–24:00 Nov 19 23:00–24:00 Nov 20 00:00–01:00, 10:00–12:00, 20:00–23:00 Nov 21 17:00–18:00 Nov 22 13:00–15:00 Nov 25 18:00–22:00 Nov 26 19:00–21:00 Nov 27 18:00–20:00
December
Dec 3 10:00–11:00, 14:00–16:00 Dec 4 18:00–21:00 Dec 8 18:00–20:00 Dec 9 20:00–22:00 Dec 11 20:00–22:00 Dec 12 16:00–18:00 Dec 16 14:00–16:00 Dec 17 19:00–23:00 Dec 19 16:00–19:00 Dec 23 21:00–23:00 Dec 27 17:00–18:00 Dec 28 15:00–17:00