Most often in August, 31 days.
Highest follower count seen that year: 41,065.
January
Jan 1 19:00–22:00 Jan 2 18:00–22:00 Jan 3 18:00–20:00 Jan 4 17:00–20:00 Jan 5 19:00–21:00 Jan 6 20:00–22:00 Jan 7 18:00–23:00 Jan 8 17:00–18:00 Jan 9 17:00–20:00 Jan 10 15:00–17:00 Jan 11 16:00–19:00 Jan 13 16:00–21:00 Jan 14 17:00–22:00 Jan 16 20:00–21:00 Jan 17 19:00–22:00 Jan 18 16:00–18:00 Jan 21 18:00–23:00 Jan 23 17:00–21:00 Jan 24 17:00–20:00 Jan 25 18:00–20:00 Jan 27 17:00–22:00 Jan 28 18:00–22:00 Jan 30 17:00–18:00, 20:00–21:00
February
Feb 1 16:00–19:00 Feb 2 17:00–20:00 Feb 3 17:00–22:00 Feb 4 18:00–20:00 Feb 5 19:00–20:00 Feb 6 18:00–21:00 Feb 7 18:00–21:00 Feb 8 18:00–19:00 Feb 9 16:00–19:00 Feb 10 18:00–21:00 Feb 11 17:00–20:00 Feb 12 16:00–18:00, 21:00–23:00 Feb 13 16:00–18:00, 20:00–21:00 Feb 14 17:00–21:00 Feb 15 15:00–18:00 Feb 16 19:00–20:00 Feb 17 20:00–21:00 Feb 18 20:00–22:00 Feb 19 21:00–22:00 Feb 20 22:00–24:00 Feb 21 19:00–20:00 Feb 22 16:00–17:00 Feb 25 19:00–20:00
March
Mar 1 17:00–21:00 Mar 2 16:00–20:00 Mar 3 18:00–21:00 Mar 4 17:00–20:00 Mar 5 19:00–21:00 Mar 6 17:00–18:00 Mar 7 18:00–19:00 Mar 8 17:00–20:00 Mar 9 21:00–22:00 Mar 10 17:00–18:00 Mar 11 18:00–20:00 Mar 12 16:00–18:00 Mar 13 18:00–20:00 Mar 14 17:00–19:00 Mar 16 17:00–19:00 Mar 17 17:00–20:00 Mar 18 17:00–19:00 Mar 19 17:00–20:00 Mar 20 17:00–19:00 Mar 21 17:00–20:00 Mar 22 14:00–17:00 Mar 23 21:00–23:00 Mar 24 18:00–19:00 Mar 25 17:00–20:00 Mar 26 16:00–19:00 Mar 27 18:00–19:00 Mar 28 17:00–19:00 Mar 29 14:00–16:00
April
Apr 1 16:00–19:00 Apr 2 17:00–19:00 Apr 3 16:00–18:00 Apr 4 18:00–20:00 Apr 5 14:00–16:00 Apr 6 19:00–21:00 Apr 7 18:00–20:00 Apr 9 16:00–18:00 Apr 10 16:00–20:00 Apr 11 16:00–20:00 Apr 12 15:00–17:00 Apr 13 14:00–17:00 Apr 14 17:00–20:00 Apr 15 16:00–17:00 Apr 16 17:00–20:00 Apr 17 17:00–19:00 Apr 18 18:00–19:00 Apr 21 18:00–19:00 Apr 22 17:00–18:00 Apr 23 17:00–18:00 Apr 24 18:00–21:00 Apr 25 18:00–20:00 Apr 27 18:00–19:00
May
May 1 15:00–21:00 May 2 17:00–20:00 May 3 16:00–20:00 May 4 18:00–19:00 May 5 19:00–21:00 May 6 16:00–20:00 May 7 16:00–19:00 May 8 17:00–21:00 May 9 17:00–21:00 May 10 16:00–20:00 May 11 17:00–19:00 May 12 19:00–21:00 May 13 17:00–21:00 May 14 17:00–20:00 May 15 17:00–20:00 May 16 19:00–21:00 May 17 16:00–20:00 May 18 14:00–16:00 May 19 15:00–20:00 May 20 19:00–20:00 May 21 17:00–21:00 May 24 17:00–20:00 May 26 17:00–20:00 May 27 17:00–18:00 May 28 17:00–20:00 May 29 19:00–20:00 May 31 18:00–19:00
June
Jun 1 16:00–20:00 Jun 2 18:00–20:00 Jun 3 16:00–21:00 Jun 4 19:00–21:00 Jun 5 17:00–21:00 Jun 6 18:00–21:00 Jun 7 16:00–19:00 Jun 8 15:00–20:00 Jun 9 18:00–20:00 Jun 10 16:00–21:00 Jun 11 17:00–20:00 Jun 12 17:00–18:00 Jun 13 15:00–19:00 Jun 14 15:00–19:00 Jun 15 17:00–19:00 Jun 16 17:00–21:00 Jun 17 16:00–19:00 Jun 18 16:00–20:00 Jun 19 17:00–20:00 Jun 20 17:00–18:00 Jun 21 16:00–19:00 Jun 22 17:00–18:00 Jun 23 16:00–19:00 Jun 26 17:00–20:00 Jun 27 17:00–19:00
July
Jul 1 17:00–21:00 Jul 2 17:00–21:00 Jul 3 17:00–20:00 Jul 4 18:00–19:00 Jul 5 16:00–20:00 Jul 6 17:00–21:00 Jul 7 17:00–20:00 Jul 8 17:00–20:00 Jul 9 17:00–20:00 Jul 10 17:00–19:00 Jul 11 18:00–21:00 Jul 12 15:00–18:00 Jul 13 19:00–20:00 Jul 14 17:00–20:00 Jul 15 18:00–19:00 Jul 16 17:00–20:00 Jul 17 17:00–19:00 Jul 18 19:00–20:00 Jul 19 15:00–17:00 Jul 20 17:00–19:00 Jul 21 17:00–20:00 Jul 22 17:00–19:00 Jul 23 18:00–20:00 Jul 25 17:00–19:00 Jul 26 14:00–15:00 Jul 27 15:00–16:00 Jul 28 17:00–20:00 Jul 29 17:00–18:00 Jul 31 18:00–19:00
August
Aug 1 15:00–20:00 Aug 2 15:00–19:00 Aug 3 16:00–18:00 Aug 4 18:00–20:00 Aug 5 17:00–18:00 Aug 6 18:00–21:00 Aug 7 17:00–18:00 Aug 8 19:00–21:00 Aug 9 16:00–19:00 Aug 10 14:00–15:00 Aug 11 17:00–20:00 Aug 12 18:00–21:00 Aug 13 18:00–20:00 Aug 14 17:00–20:00 Aug 15 22:00–23:00 Aug 16 15:00–19:00 Aug 17 16:00–19:00 Aug 18 17:00–20:00 Aug 19 15:00–20:00 Aug 20 17:00–19:00 Aug 21 16:00–19:00 Aug 22 16:00–19:00 Aug 23 16:00–17:00 Aug 24 16:00–17:00 Aug 25 18:00–21:00 Aug 26 17:00–20:00 Aug 27 18:00–20:00 Aug 28 18:00–20:00 Aug 29 16:00–19:00 Aug 30 15:00–17:00 Aug 31 17:00–19:00
September
Sep 1 15:00–19:00 Sep 2 16:00–21:00 Sep 3 17:00–21:00 Sep 4 16:00–20:00 Sep 5 17:00–19:00 Sep 6 15:00–19:00 Sep 7 17:00–18:00 Sep 8 16:00–20:00 Sep 9 16:00–17:00 Sep 10 18:00–21:00 Sep 11 17:00–20:00 Sep 12 17:00–20:00 Sep 13 15:00–17:00 Sep 14 14:00–15:00 Sep 15 17:00–20:00 Sep 16 18:00–21:00 Sep 17 18:00–20:00 Sep 18 18:00–19:00 Sep 19 16:00–20:00 Sep 20 15:00–19:00 Sep 21 15:00–17:00 Sep 22 17:00–20:00 Sep 23 17:00–21:00 Sep 24 19:00–21:00 Sep 25 17:00–19:00 Sep 26 16:00–20:00 Sep 27 14:00–15:00 Sep 28 17:00–20:00 Sep 29 18:00–19:00
October
Oct 1 15:00–21:00 Oct 2 16:00–17:00, 19:00–20:00 Oct 3 18:00–22:00 Oct 4 15:00–19:00 Oct 5 16:00–19:00 Oct 6 18:00–20:00 Oct 7 17:00–19:00 Oct 8 18:00–19:00 Oct 9 18:00–19:00 Oct 10 17:00–19:00 Oct 11 16:00–18:00 Oct 12 17:00–19:00 Oct 13 16:00–19:00 Oct 14 18:00–20:00 Oct 15 18:00–20:00 Oct 16 17:00–20:00 Oct 17 17:00–20:00 Oct 18 16:00–20:00 Oct 19 16:00–19:00 Oct 20 18:00–21:00 Oct 21 19:00–21:00 Oct 22 18:00–20:00 Oct 23 17:00–20:00 Oct 24 16:00–20:00 Oct 25 19:00–20:00 Oct 26 15:00–18:00 Oct 27 17:00–19:00 Oct 29 17:00–20:00
November
Nov 1 13:00–14:00 Nov 2 14:00–17:00 Nov 4 19:00–21:00 Nov 5 17:00–18:00, 20:00–21:00 Nov 6 16:00–19:00, 21:00–22:00 Nov 7 17:00–20:00 Nov 8 13:00–17:00, 22:00–23:00 Nov 9 17:00–18:00, 22:00–23:00 Nov 10 19:00–20:00 Nov 11 16:00–21:00 Nov 12 19:00–20:00 Nov 13 17:00–23:00 Nov 14 19:00–20:00 Nov 15 14:00–15:00, 18:00–19:00 Nov 16 17:00–20:00 Nov 17 19:00–21:00 Nov 18 19:00–21:00 Nov 19 16:00–21:00 Nov 20 18:00–20:00 Nov 21 16:00–19:00 Nov 22 13:00–19:00 Nov 23 16:00–19:00 Nov 24 16:00–20:00 Nov 28 18:00–22:00 Nov 29 16:00–19:00
December
Dec 1 17:00–21:00 Dec 2 18:00–21:00 Dec 3 19:00–21:00 Dec 4 19:00–21:00 Dec 5 18:00–21:00 Dec 6 16:00–17:00 Dec 7 18:00–19:00 Dec 8 18:00–22:00 Dec 9 16:00–20:00 Dec 10 19:00–22:00 Dec 11 18:00–21:00 Dec 12 19:00–20:00 Dec 13 15:00–19:00 Dec 16 19:00–21:00 Dec 17 18:00–20:00 Dec 18 17:00–21:00 Dec 20 15:00–16:00 Dec 21 16:00–17:00 Dec 22 18:00–21:00 Dec 26 18:00–21:00 Dec 27 17:00–18:00 Dec 29 17:00–20:00