Most often in May, 27 days.
Highest follower count seen that year: 18,456.
January
Jan 3 14:00–24:00 Jan 14 09:00–19:00 Jan 15 06:00–20:00 Jan 16 09:00–15:00, 17:00–20:00 Jan 17 04:00–10:00, 12:00–20:00 Jan 18 03:00–10:00, 17:00–19:00 Jan 19 17:00–19:00 Jan 20 05:00–18:00 Jan 21 05:00–10:00, 17:00–19:00 Jan 22 05:00–17:00 Jan 23 02:00–11:00 Jan 24 02:00–10:00, 16:00–17:00 Jan 25 02:00–04:00 Jan 26 02:00–05:00 Jan 27 02:00–17:00 Jan 28 05:00–13:00 Jan 29 02:00–12:00, 15:00–17:00 Jan 30 02:00–12:00 Jan 31 05:00–12:00
February
Feb 1 02:00–04:00, 08:00–10:00, 12:00–14:00 Feb 2 03:00–05:00, 17:00–20:00 Feb 3 02:00–04:00, 07:00–14:00, 16:00–17:00 Feb 4 05:00–12:00 Feb 5 02:00–13:00, 16:00–17:00 Feb 6 09:00–15:00 Feb 7 02:00–17:00 Feb 8 02:00–04:00, 12:00–14:00 Feb 9 02:00–04:00, 08:00–10:00 Feb 10 02:00–13:00 Feb 11 02:00–10:00, 12:00–14:00 Feb 12 02:00–14:00, 16:00–17:00 Feb 13 05:00–15:00 Feb 14 01:00–12:00, 16:00–18:00 Feb 17 05:00–13:00, 15:00–18:00 Feb 19 15:00–17:00 Feb 20 08:00–11:00 Feb 21 08:00–11:00, 15:00–18:00 Feb 22 07:00–09:00, 12:00–14:00 Feb 23 07:00–15:00 Feb 24 01:00–06:00, 15:00–17:00 Feb 25 02:00–13:00 Feb 26 05:00–13:00, 16:00–17:00 Feb 27 02:00–10:00 Feb 28 02:00–08:00, 10:00–15:00
March
Mar 1 02:00–04:00, 08:00–15:00 Mar 3 02:00–18:00 Mar 4 05:00–12:00 Mar 5 03:00–04:00, 06:00–13:00, 16:00–17:00 Mar 6 02:00–12:00 Mar 7 02:00–15:00 Mar 8 16:00–19:00 Mar 9 02:00–03:00, 17:00–20:00 Mar 10 02:00–04:00, 15:00–17:00 Mar 12 02:00–05:00, 15:00–21:00 Mar 13 03:00–04:00 Mar 14 16:00–21:00 Mar 15 02:00–05:00, 09:00–15:00, 19:00–23:00 Mar 16 09:00–12:00, 19:00–22:00 Mar 17 05:00–18:00 Mar 18 05:00–12:00 Mar 19 05:00–14:00, 16:00–18:00 Mar 20 02:00–12:00 Mar 21 05:00–17:00 Mar 22 02:00–04:00 Mar 23 12:00–15:00, 18:00–20:00 Mar 24 05:00–17:00 Mar 25 05:00–14:00 Mar 26 02:00–13:00, 19:00–22:00 Mar 27 07:00–10:00 Mar 29 17:00–22:00 Mar 31 01:00–04:00
April
Apr 2 07:00–13:00, 18:00–21:00 Apr 3 07:00–13:00, 18:00–20:00 Apr 4 17:00–22:00 Apr 5 12:00–14:00, 18:00–21:00 Apr 6 11:00–12:00 Apr 7 15:00–17:00 Apr 8 18:00–23:00 Apr 9 16:00–18:00 Apr 10 05:00–15:00 Apr 11 05:00–18:00, 20:00–22:00 Apr 12 12:00–15:00, 21:00–23:00 Apr 13 08:00–12:00, 18:00–22:00 Apr 14 05:00–18:00 Apr 15 05:00–12:00 Apr 16 05:00–21:00 Apr 17 05:00–14:00 Apr 18 05:00–13:00, 15:00–18:00 Apr 19 11:00–14:00 Apr 20 19:00–22:00 Apr 21 05:00–14:00, 16:00–18:00 Apr 22 05:00–12:00 Apr 23 05:00–17:00 Apr 24 05:00–14:00 Apr 25 06:00–14:00, 16:00–18:00 Apr 28 02:00–03:00, 06:00–14:00 Apr 29 07:00–15:00 Apr 30 05:00–13:00, 15:00–18:00
May
May 1 12:00–19:00 May 2 05:00–08:00, 11:00–15:00 May 3 08:00–13:00, 15:00–18:00 May 4 07:00–19:00 May 5 06:00–10:00 May 10 04:00–15:00 May 11 05:00–18:00 May 12 06:00–17:00 May 13 03:00–08:00, 15:00–19:00 May 14 04:00–16:00 May 15 09:00–17:00 May 16 02:00–13:00, 15:00–17:00 May 17 05:00–18:00 May 18 05:00–14:00, 16:00–18:00 May 19 05:00–15:00 May 20 11:00–18:00 May 21 06:00–12:00, 15:00–21:00 May 22 05:00–11:00, 15:00–18:00 May 23 08:00–17:00 May 24 02:00–12:00 May 25 06:00–17:00 May 26 02:00–18:00 May 27 15:00–18:00 May 28 04:00–18:00 May 29 04:00–13:00, 17:00–19:00 May 30 09:00–21:00 May 31 04:00–20:00
June
Jun 1 03:00–20:00 Jun 3 16:00–21:00 Jun 12 12:00–18:00 Jun 13 02:00–18:00 Jun 14 02:00–14:00 Jun 15 20:00–24:00 Jun 16 00:00–01:00 Jun 18 08:00–13:00, 15:00–21:00 Jun 19 02:00–08:00, 12:00–15:00 Jun 20 02:00–10:00 Jun 23 20:00–23:00 Jun 25 10:00–18:00 Jun 26 02:00–08:00, 11:00–16:00 Jun 27 02:00–11:00, 13:00–19:00 Jun 28 09:00–18:00 Jun 29 02:00–09:00, 12:00–17:00 Jun 30 02:00–17:00
July
Jul 1 05:00–17:00 Jul 2 04:00–12:00 Jul 4 18:00–21:00 Jul 5 15:00–22:00 Jul 6 07:00–19:00 Jul 7 03:00–05:00, 13:00–20:00 Jul 8 14:00–20:00 Jul 9 04:00–08:00, 15:00–19:00 Jul 10 09:00–17:00 Jul 11 06:00–20:00 Jul 12 14:00–20:00 Jul 13 03:00–21:00 Jul 21 17:00–24:00 Jul 22 00:00–02:00, 07:00–13:00, 16:00–17:00 Jul 25 06:00–12:00 Jul 26 02:00–12:00, 14:00–18:00 Jul 27 02:00–04:00, 06:00–10:00, 15:00–21:00 Jul 28 02:00–06:00 Jul 30 09:00–18:00 Jul 31 04:00–14:00
August
Aug 3 19:00–23:00 Aug 5 06:00–13:00 Aug 6 05:00–11:00 Aug 7 06:00–14:00 Aug 9 19:00–22:00 Aug 10 19:00–22:00 Aug 11 05:00–12:00 Aug 12 05:00–13:00 Aug 13 05:00–14:00, 17:00–19:00 Aug 14 02:00–08:00, 15:00–17:00 Aug 15 02:00–08:00, 13:00–18:00 Aug 16 05:00–12:00, 16:00–20:00 Aug 17 02:00–12:00, 14:00–18:00 Aug 18 02:00–08:00, 15:00–17:00 Aug 19 05:00–17:00 Aug 20 07:00–17:00 Aug 21 05:00–13:00 Aug 26 10:00–14:00
September
Sep 1 06:00–17:00 Sep 2 02:00–04:00, 06:00–12:00 Sep 3 06:00–17:00 Sep 4 05:00–13:00 Sep 5 05:00–07:00, 09:00–16:00, 20:00–23:00 Sep 6 08:00–11:00, 13:00–18:00 Sep 7 02:00–14:00 Sep 8 06:00–16:00 Sep 9 05:00–15:00, 19:00–22:00 Sep 10 05:00–09:00 Sep 19 06:00–17:00 Sep 21 19:00–20:00 Sep 22 05:00–17:00, 20:00–22:00 Sep 23 06:00–15:00 Sep 24 06:00–16:00 Sep 25 05:00–10:00, 18:00–22:00 Sep 26 06:00–17:00 Sep 27 19:00–22:00 Sep 28 10:00–13:00, 18:00–21:00 Sep 29 06:00–16:00 Sep 30 06:00–13:00
October
Oct 1 06:00–17:00 Oct 2 05:00–10:00, 19:00–21:00 Oct 3 05:00–14:00 Oct 4 13:00–16:00, 20:00–22:00 Oct 5 09:00–13:00, 19:00–23:00 Oct 7 19:00–21:00 Oct 8 14:00–17:00, 20:00–23:00 Oct 10 14:00–17:00, 19:00–23:00 Oct 11 12:00–15:00, 19:00–23:00 Oct 12 20:00–23:00 Oct 13 15:00–17:00 Oct 14 05:00–15:00 Oct 15 05:00–16:00 Oct 16 05:00–12:00 Oct 17 06:00–15:00, 20:00–22:00 Oct 18 12:00–14:00 Oct 19 12:00–15:00, 18:00–21:00 Oct 20 05:00–16:00 Oct 22 06:00–18:00 Oct 23 05:00–11:00, 19:00–22:00 Oct 24 06:00–16:00 Oct 25 08:00–10:00, 19:00–22:00 Oct 28 05:00–15:00, 20:00–22:00 Oct 29 06:00–16:00 Oct 30 05:00–09:00, 19:00–21:00 Oct 31 06:00–17:00
November
Nov 1 06:00–15:00 Nov 2 20:00–24:00 Nov 4 18:00–21:00 Nov 5 05:00–17:00 Nov 7 06:00–17:00 Nov 8 19:00–22:00 Nov 9 18:00–22:00 Nov 10 06:00–17:00 Nov 11 06:00–15:00 Nov 12 06:00–17:00 Nov 13 06:00–11:00 Nov 14 06:00–15:00 Nov 15 09:00–14:00, 19:00–21:00 Nov 16 19:00–22:00 Nov 17 06:00–17:00 Nov 18 06:00–14:00 Nov 19 05:00–17:00 Nov 20 06:00–12:00 Nov 21 06:00–16:00 Nov 22 12:00–15:00, 19:00–22:00 Nov 23 12:00–15:00, 20:00–22:00
December
Dec 1 06:00–15:00 Dec 2 06:00–15:00 Dec 3 06:00–17:00 Dec 4 06:00–11:00 Dec 5 06:00–17:00 Dec 6 12:00–15:00, 19:00–21:00 Dec 8 06:00–17:00 Dec 9 06:00–15:00 Dec 10 06:00–18:00 Dec 11 06:00–10:00, 18:00–20:00 Dec 12 06:00–14:00 Dec 14 17:00–22:00 Dec 15 05:00–11:00, 15:00–17:00 Dec 17 14:00–18:00, 20:00–23:00 Dec 18 19:00–22:00 Dec 19 15:00–18:00, 20:00–23:00 Dec 20 13:00–16:00, 19:00–22:00 Dec 21 19:00–22:00 Dec 22 05:00–17:00 Dec 23 06:00–14:00 Dec 24 09:00–16:00 Dec 25 06:00–12:00, 20:00–22:00 Dec 26 06:00–18:00 Dec 27 07:00–19:00 Dec 28 07:00–21:00 Dec 29 06:00–10:00, 12:00–23:00