It was recently the case from April 28, 2016 to May 9, 2016 that four grahas were simultaneously retrograde, in addition to the always retrograde Rāhu and Ketu, making it a total of six grahas in retrogression. In upcoming years, a similar situation will occur in April 2017 and June 2020, where four grahas will be retrograde again. This blog post gives a list of all direction changes from 2016 to 2020, shares some interesting statistics about retrograde motion, and gives the dates when all five grahas (for a total of seven!) will be retrograde later in this century.
The list of direction changes is summarized in the table below. It gives the date and time in UTC when a corresponding configuration begins, followed by a list of grahas that are retrograde. For simplicity, the table omits Sūrya and Candra, because they are never retrograde, and also omits Rāhu and Ketu, assuming they are always retrograde, although true nodes frequently move in direct motion as per a recent blog post:
| Date | Time | Ma | Bu | Gu | Sk | Sa |
|---|---|---|---|---|---|---|
| 09.10.2015 | 14:57 | |||||
| 05.01.2016 | 13:05 | R | ||||
| 08.01.2016 | 04:27 | R | R | |||
| 25.01.2016 | 21:49 | R | ||||
| 25.03.2016 | 10:29 | R | R | |||
| 17.04.2016 | 12:17 | R | R | R | ||
| 28.04.2016 | 17:19 | R | R | R | R | |
| 09.05.2016 | 12:27 | R | R | R | ||
| 22.05.2016 | 13:19 | R | R | |||
| 29.06.2016 | 23:38 | R | ||||
| 13.08.2016 | 09:59 | |||||
| 30.08.2016 | 13:04 | R | ||||
| 22.09.2016 | 05:30 | |||||
| 19.12.2016 | 10:55 | R | ||||
| 08.01.2017 | 09:42 | |||||
| 06.02.2017 | 06:42 | R | ||||
| 04.03.2017 | 09:08 | R | R | |||
| 06.04.2017 | 05:17 | R | R | R | ||
| 09.04.2017 | 23:14 | R | R | R | R | |
| 15.04.2017 | 10:17 | R | R | R | ||
| 03.05.2017 | 16:32 | R | R | |||
| 09.06.2017 | 14:13 | R | ||||
| 13.08.2017 | 01:00 | R | R | |||
| 25.08.2017 | 11:39 | R | ||||
| 05.09.2017 | 11:29 | |||||
| 03.12.2017 | 07:33 | R | ||||
| 23.12.2017 | 01:50 | |||||
| 09.03.2018 | 04:45 | R | ||||
| 23.03.2018 | 00:18 | R | R | |||
| 15.04.2018 | 09:20 | R | ||||
| 18.04.2018 | 01:48 | R | R | |||
| 26.06.2018 | 21:01 | R | R | R | ||
| 10.07.2018 | 17:18 | R | R | |||
| 26.07.2018 | 05:02 | R | R | R | ||
| 19.08.2018 | 04:24 | R | R | |||
| 27.08.2018 | 14:01 | R | ||||
| 06.09.2018 | 11:19 | |||||
| 05.10.2018 | 19:05 | R | ||||
| 16.11.2018 | 10:50 | |||||
| 17.11.2018 | 01:33 | R | ||||
| 06.12.2018 | 21:22 | |||||
| 05.03.2019 | 18:18 | R | ||||
| 28.03.2019 | 13:58 | |||||
| 10.04.2019 | 16:53 | R | ||||
| 30.04.2019 | 01:16 | R | R | |||
| 07.07.2019 | 23:14 | R | R | R | ||
| 01.08.2019 | 03:58 | R | R | |||
| 11.08.2019 | 13:46 | R | ||||
| 18.09.2019 | 08:25 | |||||
| 31.10.2019 | 15:41 | R | ||||
| 20.11.2019 | 19:11 | |||||
| 17.02.2020 | 00:53 | R | ||||
| 10.03.2020 | 03:47 | |||||
| 11.05.2020 | 03:38 | R | ||||
| 13.05.2020 | 06:44 | R | R | |||
| 14.05.2020 | 14:33 | R | R | R | ||
| 18.06.2020 | 04:58 | R | R | R | R | |
| 25.06.2020 | 06:48 | R | R | R | ||
| 12.07.2020 | 08:26 | R | R | |||
| 09.09.2020 | 22:21 | R | R | R | ||
| 13.09.2020 | 00:47 | R | R | |||
| 29.09.2020 | 04:44 | R | ||||
| 14.10.2020 | 01:05 | R | R | |||
| 03.11.2020 | 17:49 | R | ||||
| 14.11.2020 | 00:34 |
If we take a longer period of time, from 1600 to 2400, we can gather some interesting insights as to how much time different grahas spend in retrograde motion. As shown in the small table below, Śukra spends the least time in retrogression, while Śani spends the most (more than 1/3 of the time):
| Ma | Bu | Gu | Sk | Sa |
|---|---|---|---|---|
| 9.48% | 19.16% | 30.26% | 7.22% | 36.44% |
The following table shows the percentage of time for the same period when the corresponding number of grahas are retrograde. It can be seen that usually (about 42.8862% of the time) at least one graha is retrograde and that four grahas being retrograde is a rare occurrence indeed:
| 0 | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| 30.1540% | 42.8862% | 21.6833% | 4.8027% | 0.4712% | 0.0026% |
Finally, there will be two times this century when all five grahas will be retrograde. One such period will be from April 27, 2076 to April 29, 2076 and another one from September 16, 2082 to September 18, 2082. You may wish to plan your vacation for these dates - the next event will only be in July 2223.