Most often in May, 28 days.
Highest follower count seen that year: 1,834.
April
Apr 17 13:00–21:00 Apr 18 12:00–20:00 Apr 19 13:00–14:00 Apr 20 21:00–24:00 Apr 21 01:00–03:00, 13:00–20:00 Apr 22 12:00–20:00 Apr 23 12:00–16:00 Apr 24 13:00–18:00 Apr 25 12:00–20:00 Apr 26 13:00–20:00 Apr 27 12:00–17:00, 21:00–22:00 Apr 28 12:00–14:00 Apr 29 13:00–20:00 Apr 30 15:00–20:00
May
May 1 13:00–14:00 May 2 12:00–20:00 May 3 12:00–20:00 May 4 20:00–23:00 May 6 12:00–15:00, 17:00–20:00 May 7 13:00–20:00 May 8 13:00–18:00 May 9 12:00–20:00 May 10 12:00–14:00, 16:00–20:00 May 11 19:00–24:00 May 12 00:00–02:00, 12:00–21:00 May 13 13:00–19:00 May 14 13:00–20:00 May 15 12:00–19:00 May 17 13:00–20:00 May 18 20:00–24:00 May 19 00:00–02:00, 04:00–07:00, 13:00–18:00 May 20 13:00–20:00 May 21 12:00–20:00 May 22 13:00–20:00 May 24 13:00–20:00 May 25 13:00–19:00 May 26 13:00–17:00 May 27 13:00–20:00 May 28 12:00–20:00 May 29 12:00–20:00 May 30 12:00–19:00 May 31 12:00–20:00
June
Jun 1 12:00–20:00 Jun 2 12:00–19:00 Jun 3 13:00–19:00 Jun 4 13:00–20:00 Jun 5 12:00–20:00 Jun 6 12:00–20:00 Jun 8 12:00–19:00 Jun 9 12:00–19:00 Jun 10 13:00–20:00 Jun 11 19:00–20:00 Jun 12 12:00–19:00 Jun 13 12:00–19:00 Jun 14 13:00–17:00 Jun 15 20:00–21:00 Jun 17 13:00–20:00 Jun 18 12:00–20:00 Jun 19 13:00–20:00 Jun 20 13:00–20:00 Jun 21 20:00–24:00 Jun 22 00:00–03:00, 20:00–24:00 Jun 23 00:00–03:00 Jun 24 12:00–18:00 Jun 25 12:00–21:00 Jun 26 13:00–21:00 Jun 27 13:00–20:00 Jun 28 14:00–19:00 Jun 29 12:00–19:00 Jun 30 13:00–18:00
July
Jul 2 12:00–20:00 Jul 3 13:00–20:00 Jul 4 12:00–20:00 Jul 5 12:00–20:00 Jul 6 12:00–20:00 Jul 7 12:00–19:00 Jul 9 13:00–21:00 Jul 10 12:00–20:00 Jul 11 13:00–21:00 Jul 12 13:00–20:00 Jul 13 12:00–20:00 Jul 14 12:00–18:00 Jul 15 13:00–20:00 Jul 17 12:00–20:00 Jul 18 13:00–21:00 Jul 19 13:00–20:00 Jul 20 12:00–22:00 Jul 21 14:00–20:00 Jul 22 13:00–20:00 Jul 23 13:00–19:00 Jul 25 13:00–17:00 Jul 26 13:00–22:00 Jul 27 13:00–21:00 Jul 28 13:00–20:00 Jul 29 12:00–20:00 Jul 30 13:00–23:00 Jul 31 13:00–22:00
August
Aug 2 12:00–20:00 Aug 3 12:00–22:00 Aug 4 12:00–20:00 Aug 6 13:00–19:00 Aug 7 13:00–23:00 Aug 8 12:00–20:00 Aug 9 13:00–20:00 Aug 10 13:00–23:00 Aug 11 13:00–17:00 Aug 12 13:00–20:00 Aug 13 13:00–20:00 Aug 14 12:00–20:00 Aug 15 05:00–09:00, 15:00–20:00 Aug 17 13:00–20:00 Aug 18 13:00–15:00 Aug 19 13:00–19:00 Aug 20 13:00–20:00 Aug 21 13:00–20:00 Aug 22 13:00–15:00, 17:00–19:00 Aug 23 12:00–20:00 Aug 24 12:00–20:00 Aug 25 15:00–17:00 Aug 26 13:00–19:00 Aug 27 12:00–20:00 Aug 29 13:00–20:00 Aug 30 12:00–20:00 Aug 31 06:00–24:00
September
Sep 1 00:00–02:00 Sep 16 12:00–19:00 Sep 17 12:00–20:00 Sep 18 13:00–20:00 Sep 19 13:00–19:00 Sep 20 13:00–19:00 Sep 21 14:00–20:00 Sep 22 13:00–20:00 Sep 23 13:00–20:00 Sep 24 13:00–19:00 Sep 25 13:00–14:00, 16:00–19:00 Sep 26 12:00–20:00 Sep 27 13:00–19:00 Sep 29 12:00–20:00 Sep 30 12:00–19:00
October
Oct 1 13:00–20:00 Oct 3 13:00–20:00 Oct 4 13:00–20:00 Oct 5 14:00–20:00 Oct 6 12:00–19:00 Oct 7 13:00–19:00 Oct 8 13:00–20:00 Oct 9 13:00–20:00 Oct 10 13:00–20:00 Oct 11 13:00–20:00 Oct 12 12:00–13:00 Oct 14 13:00–19:00 Oct 15 14:00–19:00 Oct 20 12:00–19:00 Oct 21 13:00–20:00 Oct 22 13:00–19:00 Oct 23 12:00–19:00 Oct 24 13:00–20:00 Oct 25 13:00–20:00 Oct 26 14:00–20:00 Oct 28 13:00–19:00 Oct 29 13:00–20:00 Oct 30 13:00–20:00 Oct 31 13:00–20:00
November
Nov 1 13:00–19:00 Nov 2 13:00–20:00 Nov 4 13:00–20:00 Nov 5 13:00–20:00 Nov 6 12:00–20:00 Nov 7 13:00–20:00 Nov 8 13:00–20:00 Nov 9 12:00–20:00 Nov 10 12:00–18:00 Nov 11 13:00–20:00 Nov 12 13:00–16:00 Nov 13 13:00–15:00, 18:00–20:00 Nov 14 13:00–19:00 Nov 15 14:00–20:00 Nov 16 13:00–20:00 Nov 17 13:00–20:00 Nov 18 12:00–20:00 Nov 20 13:00–20:00 Nov 21 13:00–20:00 Nov 22 13:00–18:00 Nov 23 13:00–20:00 Nov 24 13:00–20:00 Nov 25 12:00–20:00 Nov 27 13:00–19:00 Nov 28 13:00–20:00 Nov 29 13:00–20:00 Nov 30 13:00–20:00
December
Dec 1 12:00–20:00 Dec 2 12:00–20:00 Dec 3 13:00–18:00 Dec 5 13:00–20:00 Dec 6 13:00–20:00 Dec 7 14:00–19:00, 21:00–24:00 Dec 8 00:00–01:00 Dec 9 14:00–20:00 Dec 10 13:00–20:00 Dec 11 13:00–16:00 Dec 12 13:00–20:00 Dec 13 13:00–20:00 Dec 14 13:00–20:00 Dec 15 13:00–19:00 Dec 17 03:00–11:00 Dec 18 03:00–11:00 Dec 20 04:00–12:00 Dec 21 04:00–11:00 Dec 22 04:00–12:00 Dec 23 04:00–08:00, 10:00–12:00 Dec 25 04:00–12:00 Dec 27 04:00–06:00, 08:00–12:00 Dec 28 03:00–12:00 Dec 29 04:00–06:00, 08:00–12:00 Dec 30 04:00–12:00 Dec 31 04:00–12:00, 23:00–24:00