Most often in August, 31 days.
Highest follower count seen that year: 1,122.
July
Jul 25 21:00–22:00 Jul 26 17:00–18:00, 23:00–24:00 Jul 27 00:00–01:00, 17:00–18:00, 21:00–22:00 Jul 28 19:00–21:00 Jul 29 21:00–23:00 Jul 30 20:00–21:00, 23:00–24:00 Jul 31 00:00–01:00, 20:00–24:00
August
Aug 1 00:00–02:00, 21:00–24:00 Aug 2 00:00–01:00, 17:00–19:00, 21:00–23:00 Aug 3 17:00–23:00 Aug 4 18:00–22:00 Aug 5 19:00–22:00 Aug 6 19:00–24:00 Aug 7 00:00–01:00, 20:00–24:00 Aug 8 20:00–23:00 Aug 9 17:00–18:00, 20:00–24:00 Aug 10 07:00–09:00, 22:00–24:00 Aug 11 12:00–14:00, 22:00–23:00 Aug 12 00:00–02:00, 20:00–24:00 Aug 13 18:00–22:00 Aug 14 00:00–02:00, 08:00–10:00, 15:00–17:00, 19:00–20:00 Aug 15 16:00–17:00, 19:00–21:00, 23:00–24:00 Aug 16 00:00–01:00, 18:00–19:00 Aug 17 00:00–02:00, 07:00–09:00, 17:00–18:00 Aug 18 00:00–01:00, 09:00–10:00, 16:00–18:00, 20:00–22:00 Aug 19 01:00–02:00, 08:00–10:00, 15:00–16:00, 21:00–23:00 Aug 20 17:00–19:00 Aug 21 18:00–22:00 Aug 22 09:00–10:00, 20:00–22:00 Aug 23 09:00–10:00, 15:00–18:00, 20:00–21:00 Aug 24 08:00–10:00, 16:00–21:00 Aug 25 02:00–03:00, 16:00–17:00, 20:00–21:00 Aug 26 20:00–21:00 Aug 27 19:00–20:00 Aug 28 16:00–22:00 Aug 29 17:00–20:00, 23:00–24:00 Aug 30 00:00–02:00, 16:00–21:00 Aug 31 19:00–21:00, 23:00–24:00
September
Sep 1 00:00–01:00, 16:00–17:00, 19:00–21:00 Sep 2 18:00–19:00, 21:00–22:00 Sep 3 00:00–01:00, 19:00–20:00, 22:00–23:00 Sep 4 15:00–16:00, 18:00–19:00 Sep 5 18:00–19:00, 22:00–23:00 Sep 6 15:00–16:00, 19:00–21:00 Sep 7 15:00–16:00, 20:00–21:00 Sep 8 18:00–19:00, 21:00–22:00 Sep 9 16:00–17:00, 19:00–22:00 Sep 10 14:00–15:00, 20:00–21:00 Sep 11 20:00–21:00 Sep 12 18:00–20:00, 22:00–23:00 Sep 13 20:00–21:00 Sep 14 18:00–20:00 Sep 15 20:00–21:00 Sep 18 18:00–21:00 Sep 19 20:00–21:00 Sep 20 16:00–18:00 Sep 21 16:00–17:00, 20:00–21:00, 23:00–24:00 Sep 22 00:00–01:00, 21:00–22:00 Sep 23 19:00–20:00, 22:00–24:00 Sep 24 18:00–22:00 Sep 25 18:00–24:00 Sep 26 18:00–20:00, 22:00–23:00 Sep 27 17:00–18:00, 21:00–23:00 Sep 28 01:00–02:00, 21:00–22:00 Sep 29 22:00–23:00 Sep 30 21:00–22:00
October
Oct 1 20:00–21:00 Oct 3 00:00–01:00 Oct 6 00:00–02:00 Oct 7 21:00–22:00 Oct 8 18:00–19:00 Oct 9 18:00–20:00 Oct 13 20:00–22:00 Oct 14 20:00–22:00 Oct 15 19:00–20:00 Oct 16 18:00–21:00 Oct 17 18:00–22:00 Oct 18 18:00–22:00 Oct 19 01:00–03:00, 17:00–22:00 Oct 20 14:00–15:00, 19:00–23:00 Oct 21 20:00–22:00 Oct 22 00:00–02:00, 10:00–11:00, 18:00–23:00 Oct 23 20:00–24:00 Oct 24 12:00–14:00, 18:00–23:00 Oct 25 21:00–24:00 Oct 26 15:00–19:00, 22:00–23:00 Oct 27 00:00–01:00, 16:00–19:00, 21:00–24:00 Oct 28 16:00–17:00, 19:00–20:00, 23:00–24:00 Oct 29 17:00–24:00 Oct 30 00:00–01:00, 04:00–05:00, 15:00–16:00, 19:00–23:00 Oct 31 02:00–03:00, 18:00–24:00
November
Nov 1 01:00–04:00, 20:00–24:00 Nov 2 00:00–01:00, 17:00–24:00 Nov 3 18:00–22:00 Nov 4 00:00–01:00, 19:00–20:00, 22:00–23:00 Nov 5 18:00–19:00, 22:00–23:00 Nov 6 18:00–19:00, 23:00–24:00 Nov 7 02:00–03:00, 20:00–24:00 Nov 8 18:00–19:00, 22:00–23:00 Nov 9 18:00–24:00 Nov 10 00:00–01:00, 03:00–04:00, 18:00–19:00, 22:00–24:00 Nov 11 00:00–01:00, 18:00–21:00 Nov 12 00:00–01:00, 17:00–19:00, 22:00–23:00 Nov 13 19:00–24:00 Nov 14 00:00–02:00, 19:00–24:00 Nov 15 00:00–02:00, 19:00–24:00 Nov 16 00:00–02:00 Nov 17 01:00–03:00, 20:00–24:00 Nov 18 02:00–03:00, 23:00–24:00 Nov 19 00:00–03:00, 19:00–21:00 Nov 20 19:00–20:00 Nov 21 15:00–16:00, 22:00–23:00 Nov 22 17:00–18:00, 22:00–23:00 Nov 23 15:00–17:00, 23:00–24:00 Nov 24 00:00–01:00 Nov 25 17:00–19:00 Nov 26 19:00–20:00, 23:00–24:00 Nov 27 13:00–14:00, 21:00–23:00 Nov 28 16:00–18:00, 20:00–21:00 Nov 29 18:00–20:00 Nov 30 21:00–22:00
December
Dec 2 20:00–23:00 Dec 3 18:00–20:00, 23:00–24:00 Dec 4 23:00–24:00 Dec 6 19:00–21:00 Dec 7 17:00–19:00 Dec 9 23:00–24:00 Dec 12 19:00–20:00, 22:00–23:00 Dec 13 17:00–21:00, 23:00–24:00 Dec 14 15:00–17:00, 20:00–21:00 Dec 15 18:00–21:00 Dec 16 01:00–02:00, 16:00–17:00, 19:00–21:00 Dec 17 17:00–23:00 Dec 18 14:00–15:00, 17:00–24:00 Dec 19 15:00–17:00, 19:00–23:00 Dec 20 01:00–03:00, 12:00–13:00, 19:00–22:00 Dec 21 11:00–12:00, 14:00–15:00, 18:00–21:00 Dec 22 01:00–02:00, 18:00–19:00, 22:00–23:00 Dec 23 18:00–24:00 Dec 24 20:00–23:00 Dec 25 22:00–23:00 Dec 26 19:00–24:00 Dec 27 17:00–24:00 Dec 28 02:00–04:00, 14:00–15:00, 21:00–22:00 Dec 29 00:00–03:00, 15:00–21:00, 23:00–24:00 Dec 30 00:00–01:00, 14:00–18:00, 20:00–24:00 Dec 31 00:00–01:00, 17:00–19:00, 23:00–24:00