Most often in October, 21 days.
Highest follower count seen that year: 15,385.
January
Jan 5 20:00–24:00 Jan 8 22:00–24:00 Jan 9 00:00–01:00 Jan 10 15:00–17:00, 21:00–24:00 Jan 11 00:00–01:00, 03:00–04:00 Jan 13 20:00–24:00 Jan 14 00:00–05:00, 23:00–24:00 Jan 15 00:00–04:00, 21:00–24:00 Jan 16 00:00–01:00, 14:00–16:00, 21:00–24:00 Jan 17 00:00–01:00 Jan 24 21:00–24:00 Jan 25 00:00–01:00 Jan 30 21:00–23:00
February
Feb 4 21:00–24:00 Feb 5 20:00–24:00 Feb 6 00:00–01:00 Feb 7 20:00–22:00 Feb 8 13:00–18:00 Feb 9 21:00–24:00 Feb 10 22:00–24:00 Feb 11 00:00–02:00, 14:00–15:00, 21:00–24:00 Feb 12 21:00–24:00 Feb 13 00:00–02:00, 22:00–24:00 Feb 14 00:00–02:00 Feb 15 19:00–24:00 Feb 16 00:00–01:00, 23:00–24:00 Feb 17 00:00–03:00, 22:00–24:00 Feb 18 00:00–02:00, 20:00–24:00 Feb 19 00:00–01:00, 21:00–24:00 Feb 20 00:00–01:00 Feb 24 22:00–24:00 Feb 25 00:00–01:00 Feb 26 06:00–09:00 Feb 28 14:00–17:00, 22:00–23:00
March
Mar 3 21:00–24:00 Mar 4 00:00–05:00, 23:00–24:00 Mar 5 00:00–06:00, 22:00–24:00 Mar 6 00:00–02:00 Mar 7 23:00–24:00 Mar 8 00:00–03:00 Mar 14 08:00–09:00 Mar 17 10:00–13:00 Mar 19 08:00–11:00 Mar 20 13:00–14:00, 21:00–24:00 Mar 21 00:00–02:00 Mar 23 21:00–24:00 Mar 24 08:00–14:00, 20:00–23:00 Mar 25 08:00–13:00, 21:00–23:00 Mar 26 09:00–14:00 Mar 27 12:00–13:00 Mar 29 12:00–15:00 Mar 30 19:00–21:00 Mar 31 11:00–14:00, 20:00–23:00
April
Apr 1 11:00–15:00, 20:00–22:00 Apr 2 10:00–13:00, 20:00–22:00 Apr 3 13:00–15:00, 20:00–23:00 Apr 10 19:00–23:00 Apr 11 20:00–22:00 Apr 12 14:00–15:00 Apr 14 12:00–14:00, 20:00–23:00 Apr 15 12:00–14:00 Apr 16 06:00–09:00, 12:00–15:00, 22:00–23:00 Apr 17 12:00–13:00 Apr 18 21:00–23:00 Apr 23 12:00–16:00 Apr 25 12:00–15:00 Apr 26 12:00–15:00, 21:00–24:00
May
May 2 21:00–23:00 May 3 13:00–15:00, 20:00–23:00 May 4 09:00–11:00 May 5 12:00–14:00, 20:00–22:00 May 7 09:00–10:00, 20:00–23:00 May 8 10:00–12:00, 20:00–24:00 May 11 21:00–23:00 May 13 21:00–23:00 May 14 07:00–08:00, 10:00–11:00 May 20 09:00–10:00, 12:00–14:00 May 21 14:00–16:00
June
Jun 9 20:00–23:00 Jun 10 14:00–15:00, 20:00–23:00 Jun 11 14:00–17:00 Jun 12 15:00–18:00, 20:00–23:00 Jun 13 11:00–12:00 Jun 14 11:00–13:00 Jun 16 22:00–24:00 Jun 17 00:00–01:00, 13:00–17:00, 21:00–24:00 Jun 18 20:00–24:00 Jun 19 00:00–01:00, 13:00–16:00, 21:00–23:00 Jun 21 12:00–15:00 Jun 22 14:00–17:00 Jun 23 10:00–15:00, 21:00–23:00 Jun 24 13:00–15:00, 22:00–24:00 Jun 26 14:00–16:00 Jun 27 21:00–24:00 Jun 28 00:00–01:00 Jun 29 13:00–17:00, 22:00–24:00 Jun 30 00:00–01:00
July
Jul 1 15:00–17:00 Jul 2 21:00–24:00 Jul 3 14:00–15:00, 20:00–23:00 Jul 4 22:00–24:00 Jul 5 14:00–15:00, 20:00–24:00 Jul 8 14:00–16:00, 19:00–22:00 Jul 9 21:00–23:00 Jul 10 08:00–14:00, 20:00–24:00 Jul 11 20:00–24:00 Jul 13 21:00–23:00 Jul 16 13:00–15:00, 20:00–22:00 Jul 18 13:00–14:00, 21:00–23:00 Jul 21 13:00–17:00, 20:00–23:00 Jul 22 14:00–16:00 Jul 23 13:00–15:00, 20:00–22:00 Jul 24 13:00–16:00 Jul 27 23:00–24:00 Jul 28 13:00–16:00 Jul 29 21:00–24:00 Jul 30 00:00–01:00, 14:00–15:00, 20:00–22:00
August
Aug 2 21:00–22:00 Aug 5 20:00–22:00 Aug 27 10:00–13:00 Aug 29 19:00–20:00
September
Sep 1 20:00–23:00 Sep 2 10:00–13:00, 20:00–24:00 Sep 5 10:00–12:00 Sep 8 20:00–23:00 Sep 10 20:00–24:00 Sep 12 19:00–21:00 Sep 15 14:00–15:00 Sep 16 20:00–23:00 Sep 17 15:00–17:00, 20:00–22:00 Sep 18 08:00–15:00, 19:00–22:00 Sep 19 19:00–22:00 Sep 20 12:00–14:00 Sep 22 20:00–23:00 Sep 23 11:00–14:00 Sep 24 19:00–20:00 Sep 25 06:00–07:00 Sep 28 19:00–21:00 Sep 29 06:00–10:00, 12:00–13:00 Sep 30 20:00–21:00
October
Oct 1 20:00–23:00 Oct 2 07:00–08:00, 11:00–13:00 Oct 4 12:00–13:00 Oct 7 22:00–23:00 Oct 9 11:00–13:00, 20:00–23:00 Oct 10 20:00–23:00 Oct 11 00:00–03:00 Oct 15 19:00–20:00 Oct 17 00:00–02:00, 21:00–24:00 Oct 18 00:00–01:00, 21:00–24:00 Oct 19 00:00–02:00, 20:00–24:00 Oct 20 00:00–02:00, 20:00–24:00 Oct 21 00:00–02:00, 21:00–22:00 Oct 23 20:00–22:00 Oct 24 08:00–09:00, 11:00–12:00, 19:00–24:00 Oct 25 20:00–24:00 Oct 26 00:00–01:00, 20:00–24:00 Oct 27 00:00–02:00, 11:00–13:00, 21:00–24:00 Oct 29 02:00–06:00, 22:00–24:00 Oct 30 00:00–01:00, 21:00–24:00 Oct 31 00:00–02:00
November
Nov 1 21:00–24:00 Nov 2 00:00–01:00 Nov 5 21:00–24:00 Nov 6 00:00–01:00 Nov 10 21:00–24:00 Nov 11 00:00–01:00 Nov 17 23:00–24:00 Nov 18 00:00–02:00, 21:00–24:00 Nov 19 00:00–01:00, 21:00–24:00 Nov 20 00:00–02:00, 21:00–24:00 Nov 21 20:00–24:00 Nov 22 01:00–03:00 Nov 23 19:00–22:00 Nov 24 05:00–09:00, 11:00–14:00, 22:00–24:00 Nov 25 00:00–02:00 Nov 27 19:00–23:00 Nov 28 05:00–14:00, 22:00–24:00 Nov 29 00:00–02:00
December
Dec 4 21:00–24:00 Dec 5 00:00–02:00, 20:00–24:00 Dec 6 19:00–23:00 Dec 7 00:00–01:00, 22:00–24:00 Dec 8 00:00–01:00, 20:00–24:00 Dec 9 00:00–03:00, 21:00–24:00 Dec 10 00:00–02:00 Dec 14 21:00–24:00 Dec 15 00:00–01:00, 21:00–24:00 Dec 16 00:00–02:00, 20:00–24:00 Dec 17 00:00–02:00, 21:00–24:00 Dec 18 00:00–03:00, 22:00–23:00 Dec 19 08:00–11:00, 13:00–16:00 Dec 20 21:00–24:00 Dec 21 00:00–03:00 Dec 22 22:00–24:00 Dec 23 00:00–02:00 Dec 29 20:00–24:00 Dec 30 00:00–03:00, 21:00–24:00 Dec 31 00:00–01:00, 11:00–14:00, 23:00–24:00