Most often in May, 31 days.
Highest follower count seen that year: 45,032.
January
Jan 1 14:00–18:00 Jan 2 14:00–17:00 Jan 3 14:00–17:00 Jan 4 14:00–17:00 Jan 5 14:00–17:00 Jan 6 12:00–16:00 Jan 8 13:00–16:00 Jan 9 13:00–16:00 Jan 10 13:00–16:00 Jan 11 13:00–16:00 Jan 12 13:00–17:00 Jan 13 13:00–16:00 Jan 14 13:00–15:00 Jan 15 14:00–15:00 Jan 16 12:00–15:00 Jan 17 12:00–16:00 Jan 18 13:00–16:00 Jan 19 13:00–15:00 Jan 23 13:00–16:00 Jan 24 14:00–16:00 Jan 25 13:00–16:00 Jan 26 13:00–16:00 Jan 27 13:00–16:00 Jan 28 13:00–16:00 Jan 29 13:00–16:00 Jan 30 13:00–16:00 Jan 31 12:00–15:00
February
Feb 1 13:00–16:00 Feb 2 13:00–16:00 Feb 3 12:00–15:00 Feb 4 08:00–11:00 Feb 5 08:00–11:00 Feb 6 08:00–11:00 Feb 7 07:00–10:00 Feb 8 13:00–16:00 Feb 9 13:00–17:00 Feb 10 12:00–15:00 Feb 11 08:00–11:00 Feb 12 08:00–11:00 Feb 13 12:00–15:00 Feb 14 12:00–15:00 Feb 15 13:00–16:00 Feb 16 13:00–16:00 Feb 17 12:00–14:00 Feb 18 13:00–16:00 Feb 19 12:00–15:00 Feb 20 12:00–15:00 Feb 21 12:00–15:00 Feb 22 13:00–16:00 Feb 23 13:00–16:00 Feb 24 08:00–10:00 Feb 25 08:00–10:00 Feb 26 08:00–10:00 Feb 27 12:00–15:00 Feb 28 12:00–14:00
March
Mar 1 13:00–15:00 Mar 2 13:00–16:00 Mar 3 11:00–14:00 Mar 4 11:00–14:00 Mar 5 09:00–13:00 Mar 6 10:00–13:00 Mar 7 10:00–12:00 Mar 8 13:00–15:00 Mar 9 13:00–17:00 Mar 10 08:00–11:00 Mar 11 08:00–10:00 Mar 12 11:00–14:00 Mar 13 13:00–14:00 Mar 14 08:00–10:00 Mar 15 13:00–15:00 Mar 16 13:00–15:00 Mar 17 08:00–09:00 Mar 18 17:00–20:00 Mar 19 08:00–09:00, 17:00–18:00 Mar 20 13:00–14:00, 17:00–19:00 Mar 21 12:00–15:00 Mar 22 13:00–16:00 Mar 23 13:00–16:00 Mar 24 08:00–10:00 Mar 25 08:00–11:00 Mar 26 13:00–15:00 Mar 27 09:00–11:00 Mar 28 13:00–15:00 Mar 29 13:00–17:00 Mar 30 12:00–15:00 Mar 31 12:00–14:00
April
Apr 1 07:00–08:00 Apr 2 07:00–09:00 Apr 3 16:00–17:00 Apr 4 10:00–13:00 Apr 5 13:00–15:00 Apr 6 13:00–16:00 Apr 7 11:00–14:00 Apr 8 11:00–14:00 Apr 9 12:00–14:00 Apr 10 07:00–10:00 Apr 11 07:00–09:00 Apr 12 12:00–16:00 Apr 13 11:00–15:00 Apr 14 07:00–09:00 Apr 15 07:00–08:00 Apr 16 12:00–14:00 Apr 17 08:00–10:00 Apr 18 12:00–15:00 Apr 19 11:00–14:00 Apr 20 12:00–15:00 Apr 21 11:00–14:00 Apr 22 11:00–14:00 Apr 23 13:00–15:00 Apr 24 09:00–12:00 Apr 25 10:00–12:00 Apr 26 11:00–14:00 Apr 27 11:00–13:00 Apr 28 10:00–12:00 Apr 29 13:00–15:00 Apr 30 11:00–13:00
May
May 1 09:00–11:00 May 2 08:00–12:00 May 3 11:00–14:00 May 4 11:00–15:00 May 5 09:00–12:00 May 6 12:00–15:00 May 7 08:00–11:00 May 8 11:00–14:00 May 9 09:00–13:00 May 10 11:00–13:00 May 11 10:00–14:00 May 12 07:00–10:00 May 13 07:00–10:00 May 14 07:00–10:00 May 15 07:00–10:00 May 16 07:00–10:00 May 17 09:00–12:00 May 18 11:00–14:00 May 19 07:00–10:00 May 20 07:00–10:00 May 21 07:00–10:00 May 22 07:00–10:00 May 23 11:00–14:00 May 24 11:00–15:00 May 25 12:00–15:00 May 26 07:00–09:00 May 27 08:00–11:00 May 28 09:00–12:00 May 29 09:00–12:00 May 30 09:00–12:00 May 31 09:00–12:00
June
Jun 1 09:00–13:00 Jun 2 10:00–12:00 Jun 3 07:00–10:00 Jun 4 10:00–12:00 Jun 5 10:00–12:00 Jun 6 12:00–14:00 Jun 7 10:00–13:00 Jun 8 14:00–16:00 Jun 9 10:00–13:00 Jun 10 09:00–12:00 Jun 11 10:00–13:00 Jun 12 11:00–13:00 Jun 13 10:00–13:00 Jun 14 10:00–12:00 Jun 15 11:00–14:00 Jun 16 09:00–11:00 Jun 18 09:00–12:00 Jun 19 10:00–11:00 Jun 20 10:00–13:00 Jun 21 10:00–13:00 Jun 22 09:00–12:00 Jun 23 10:00–13:00 Jun 24 10:00–12:00 Jun 25 10:00–13:00 Jun 26 09:00–12:00 Jun 27 17:00–20:00 Jun 28 10:00–13:00 Jun 29 11:00–14:00 Jun 30 10:00–12:00
July
Jul 1 09:00–13:00 Jul 2 10:00–13:00 Jul 3 09:00–12:00 Jul 4 10:00–12:00 Jul 5 10:00–12:00 Jul 6 09:00–12:00 Jul 7 10:00–13:00 Jul 8 13:00–15:00 Jul 9 09:00–12:00 Jul 10 14:00–17:00 Jul 11 08:00–10:00 Jul 16 10:00–13:00 Jul 17 11:00–13:00 Jul 18 15:00–17:00 Jul 19 10:00–12:00 Jul 20 12:00–15:00 Jul 21 10:00–13:00 Jul 22 10:00–13:00 Jul 23 10:00–12:00 Jul 24 11:00–14:00 Jul 25 11:00–15:00 Jul 26 12:00–15:00 Jul 27 10:00–12:00, 17:00–19:00 Jul 28 10:00–13:00 Jul 29 10:00–13:00 Jul 30 10:00–13:00 Jul 31 11:00–14:00
August
Aug 1 10:00–13:00 Aug 2 10:00–13:00 Aug 3 11:00–14:00 Aug 4 10:00–13:00 Aug 5 09:00–11:00 Aug 6 12:00–14:00 Aug 7 10:00–13:00 Aug 8 10:00–13:00 Aug 9 11:00–13:00 Aug 10 10:00–14:00 Aug 11 13:00–16:00 Aug 12 11:00–13:00 Aug 13 12:00–14:00 Aug 14 11:00–14:00 Aug 15 12:00–14:00 Aug 16 12:00–15:00 Aug 17 09:00–12:00 Aug 18 11:00–14:00 Aug 19 11:00–13:00 Aug 20 10:00–13:00 Aug 21 11:00–13:00 Aug 22 11:00–15:00 Aug 23 10:00–14:00 Aug 24 11:00–14:00 Aug 25 12:00–14:00 Aug 26 10:00–12:00 Aug 27 11:00–14:00 Aug 28 09:00–12:00 Aug 29 12:00–15:00 Aug 30 10:00–12:00 Aug 31 12:00–15:00
September
Sep 1 11:00–14:00 Sep 2 07:00–10:00 Sep 3 12:00–15:00 Sep 4 12:00–15:00 Sep 5 12:00–15:00 Sep 6 11:00–15:00 Sep 7 12:00–15:00 Sep 8 11:00–13:00 Sep 9 07:00–10:00 Sep 10 12:00–15:00 Sep 12 11:00–14:00 Sep 13 11:00–13:00 Sep 14 11:00–14:00 Sep 15 07:00–10:00 Sep 16 07:00–09:00 Sep 17 12:00–15:00 Sep 18 12:00–15:00 Sep 19 12:00–15:00 Sep 20 11:00–14:00 Sep 21 11:00–14:00 Sep 22 11:00–14:00 Sep 23 12:00–14:00 Sep 24 12:00–13:00 Sep 25 11:00–14:00 Sep 26 11:00–14:00 Sep 27 12:00–15:00 Sep 28 11:00–14:00 Sep 29 12:00–14:00 Sep 30 12:00–14:00
October
Oct 1 11:00–14:00 Oct 2 12:00–15:00 Oct 4 11:00–14:00 Oct 5 12:00–15:00 Oct 7 08:00–11:00 Oct 8 11:00–14:00 Oct 9 09:00–11:00 Oct 11 12:00–15:00 Oct 12 10:00–14:00 Oct 14 11:00–12:00 Oct 16 14:00–17:00 Oct 17 15:00–18:00 Oct 18 13:00–16:00 Oct 19 11:00–14:00 Oct 20 12:00–15:00 Oct 21 12:00–14:00 Oct 22 07:00–10:00 Oct 23 17:00–19:00 Oct 24 17:00–19:00 Oct 25 12:00–14:00 Oct 26 14:00–15:00 Oct 27 17:00–18:00 Oct 28 16:00–18:00 Oct 29 16:00–17:00 Oct 30 14:00–17:00 Oct 31 14:00–17:00
November
Nov 1 12:00–16:00 Nov 2 13:00–16:00 Nov 3 17:00–19:00 Nov 4 13:00–16:00 Nov 5 17:00–20:00 Nov 6 13:00–16:00 Nov 8 12:00–15:00 Nov 9 13:00–16:00 Nov 10 17:00–19:00 Nov 11 13:00–16:00 Nov 12 09:00–11:00 Nov 13 18:00–20:00 Nov 14 14:00–16:00 Nov 15 13:00–15:00 Nov 16 13:00–15:00 Nov 17 13:00–15:00 Nov 18 08:00–11:00 Nov 19 17:00–19:00 Nov 20 18:00–20:00 Nov 21 09:00–10:00 Nov 22 13:00–15:00 Nov 23 10:00–13:00 Nov 24 13:00–15:00 Nov 26 08:00–12:00 Nov 27 17:00–20:00 Nov 28 09:00–11:00 Nov 29 12:00–16:00 Nov 30 13:00–15:00
December
Dec 1 13:00–16:00 Dec 2 14:00–16:00 Dec 3 14:00–15:00 Dec 5 13:00–16:00 Dec 6 12:00–14:00 Dec 7 13:00–16:00 Dec 8 12:00–15:00 Dec 9 12:00–14:00 Dec 10 08:00–11:00