Most often in January, 22 days.
Highest follower count seen that year: 9,173.
January
Jan 1 14:00–17:00 Jan 2 09:00–10:00 Jan 8 08:00–09:00, 16:00–18:00 Jan 9 09:00–11:00 Jan 10 23:00–24:00 Jan 11 08:00–09:00, 20:00–21:00 Jan 14 13:00–16:00 Jan 15 08:00–09:00, 16:00–17:00 Jan 16 09:00–10:00 Jan 18 09:00–10:00, 17:00–18:00 Jan 19 11:00–12:00 Jan 20 09:00–11:00 Jan 21 08:00–10:00, 23:00–24:00 Jan 22 14:00–16:00 Jan 23 08:00–09:00 Jan 24 09:00–10:00 Jan 25 16:00–17:00 Jan 26 10:00–11:00 Jan 27 13:00–15:00 Jan 28 09:00–12:00 Jan 29 09:00–10:00 Jan 31 15:00–16:00
February
Feb 4 10:00–11:00, 17:00–18:00 Feb 5 15:00–17:00 Feb 6 11:00–12:00 Feb 7 09:00–11:00 Feb 8 16:00–17:00 Feb 9 14:00–16:00 Feb 10 09:00–10:00 Feb 11 13:00–14:00 Feb 12 23:00–24:00 Feb 13 00:00–01:00, 10:00–12:00, 23:00–24:00 Feb 14 16:00–17:00, 23:00–24:00 Feb 15 03:00–04:00, 16:00–17:00 Feb 16 09:00–10:00 Feb 17 09:00–11:00 Feb 18 08:00–10:00 Feb 19 08:00–09:00 Feb 20 07:00–08:00, 16:00–17:00 Feb 24 10:00–11:00 Feb 25 09:00–10:00 Feb 27 10:00–11:00, 17:00–18:00 Feb 28 17:00–18:00
March
Mar 1 16:00–17:00 Mar 4 08:00–09:00 Mar 6 08:00–09:00, 14:00–15:00 Mar 9 16:00–17:00 Mar 10 09:00–10:00 Mar 12 08:00–10:00, 17:00–18:00 Mar 13 08:00–10:00 Mar 15 08:00–09:00 Mar 18 08:00–10:00 Mar 19 08:00–09:00 Mar 20 11:00–12:00, 18:00–19:00 Mar 22 09:00–11:00 Mar 23 11:00–12:00 Mar 24 08:00–10:00 Mar 25 09:00–10:00 Mar 26 10:00–12:00 Mar 27 08:00–10:00 Mar 28 11:00–12:00
April
Apr 1 08:00–09:00 Apr 2 07:00–08:00, 14:00–15:00 Apr 3 08:00–09:00 Apr 8 07:00–08:00 Apr 10 12:00–14:00 Apr 11 08:00–10:00 Apr 13 13:00–14:00 Apr 14 16:00–17:00 Apr 15 07:00–09:00 Apr 16 15:00–16:00 Apr 29 07:00–09:00 Apr 30 18:00–19:00
May
May 6 13:00–14:00 May 7 07:00–08:00 May 9 11:00–12:00 May 12 07:00–08:00 May 13 08:00–09:00 May 14 08:00–09:00, 16:00–17:00 May 15 07:00–08:00 May 19 07:00–08:00 May 20 07:00–08:00 May 21 07:00–08:00, 14:00–15:00 May 23 08:00–09:00 May 24 22:00–23:00 May 25 23:00–24:00 May 26 08:00–09:00 May 27 07:00–09:00 May 28 15:00–16:00 May 29 07:00–09:00, 15:00–16:00
June
Jun 3 07:00–08:00, 17:00–18:00 Jun 4 07:00–08:00 Jun 5 07:00–08:00 Jun 8 01:00–02:00, 09:00–10:00, 13:00–14:00, 23:00–24:00 Jun 9 10:00–11:00, 14:00–16:00, 21:00–22:00 Jun 10 09:00–11:00, 20:00–22:00 Jun 12 09:00–10:00 Jun 16 11:00–13:00, 23:00–24:00 Jun 17 00:00–01:00, 12:00–13:00 Jun 22 22:00–24:00 Jun 23 07:00–08:00 Jun 24 12:00–14:00
July
Jul 1 18:00–19:00 Jul 4 08:00–09:00, 23:00–24:00 Jul 6 08:00–09:00, 23:00–24:00 Jul 7 08:00–09:00 Jul 8 15:00–16:00 Jul 9 00:00–01:00, 08:00–09:00, 11:00–12:00 Jul 10 10:00–11:00, 16:00–17:00 Jul 11 08:00–09:00 Jul 14 09:00–10:00 Jul 15 15:00–16:00 Jul 16 08:00–09:00, 16:00–17:00 Jul 21 00:00–01:00 Jul 22 09:00–10:00 Jul 24 15:00–16:00, 22:00–23:00 Jul 25 13:00–14:00 Jul 26 14:00–15:00 Jul 28 08:00–10:00 Jul 29 08:00–09:00, 23:00–24:00
August
Aug 3 22:00–23:00 Aug 4 07:00–08:00 Aug 8 13:00–14:00, 21:00–22:00 Aug 9 09:00–11:00 Aug 10 03:00–04:00, 10:00–11:00 Aug 11 16:00–17:00 Aug 12 06:00–07:00 Aug 13 15:00–16:00 Aug 15 23:00–24:00 Aug 16 22:00–23:00 Aug 17 14:00–15:00 Aug 21 10:00–11:00 Aug 23 12:00–14:00 Aug 25 21:00–23:00 Aug 26 21:00–23:00 Aug 27 23:00–24:00 Aug 28 00:00–01:00, 22:00–23:00 Aug 29 08:00–09:00 Aug 30 07:00–09:00, 17:00–19:00 Aug 31 15:00–16:00
September
Sep 2 10:00–11:00 Sep 3 10:00–11:00 Sep 4 14:00–15:00 Sep 6 12:00–13:00 Sep 7 16:00–17:00 Sep 9 07:00–09:00, 14:00–15:00 Sep 10 10:00–11:00, 13:00–15:00 Sep 12 13:00–14:00 Sep 13 08:00–09:00, 22:00–23:00 Sep 14 09:00–10:00 Sep 22 08:00–09:00 Sep 23 10:00–11:00 Sep 24 14:00–16:00 Sep 25 08:00–10:00 Sep 26 08:00–09:00 Sep 27 09:00–10:00, 15:00–16:00 Sep 30 09:00–10:00
October
Oct 2 21:00–22:00 Oct 5 18:00–20:00 Oct 6 21:00–22:00 Oct 8 06:00–07:00, 14:00–15:00 Oct 9 11:00–12:00 Oct 10 16:00–17:00 Oct 13 07:00–09:00, 15:00–16:00 Oct 14 09:00–11:00 Oct 15 02:00–04:00, 09:00–10:00 Oct 16 02:00–06:00, 11:00–12:00, 21:00–22:00 Oct 17 22:00–24:00 Oct 18 08:00–09:00, 23:00–24:00 Oct 19 00:00–01:00, 10:00–12:00 Oct 20 09:00–11:00, 23:00–24:00 Oct 21 09:00–10:00 Oct 22 12:00–14:00 Oct 23 09:00–10:00, 15:00–16:00 Oct 24 07:00–08:00 Oct 26 14:00–15:00 Oct 29 08:00–09:00, 14:00–16:00 Oct 30 18:00–19:00
November
Nov 1 17:00–18:00 Nov 2 09:00–10:00 Nov 3 11:00–12:00, 14:00–15:00 Nov 4 11:00–12:00, 17:00–18:00 Nov 6 09:00–11:00 Nov 7 00:00–02:00, 10:00–11:00, 23:00–24:00 Nov 8 08:00–10:00, 14:00–15:00 Nov 10 17:00–18:00 Nov 11 10:00–12:00 Nov 12 08:00–09:00, 17:00–18:00 Nov 14 08:00–09:00, 14:00–15:00 Nov 15 19:00–20:00 Nov 18 10:00–12:00 Nov 20 09:00–11:00, 15:00–17:00 Nov 21 08:00–09:00 Nov 24 10:00–12:00 Nov 25 10:00–11:00 Nov 26 08:00–10:00 Nov 27 14:00–15:00 Nov 28 18:00–19:00 Nov 30 17:00–18:00
December
Dec 1 16:00–17:00 Dec 4 16:00–17:00 Dec 5 08:00–10:00 Dec 6 10:00–11:00 Dec 7 11:00–12:00 Dec 8 22:00–23:00 Dec 9 14:00–15:00 Dec 10 13:00–14:00 Dec 11 14:00–15:00 Dec 12 13:00–15:00 Dec 14 10:00–11:00, 17:00–18:00 Dec 15 08:00–10:00 Dec 16 12:00–14:00 Dec 17 20:00–21:00 Dec 18 10:00–12:00, 17:00–19:00 Dec 19 08:00–09:00 Dec 21 14:00–15:00 Dec 22 12:00–14:00 Dec 24 10:00–11:00, 16:00–17:00 Dec 26 17:00–18:00