A first installation occurs at the relevant 1st Pentecost festival date, a 2nd installation at the 2nd Pentecost festival date, a 3rd at the 3rd and so on

Under law if someone celebrated Nisan14 then then had to give their first fruits offering on 1NC first fruits. Then they should celebrate the 1NC Pentecost. But if they failed to do that they could celebrate instead the late 1NC Pentecost. Since some people must have done that, their actions establish a necessary prophetic fulfilment wherein an installation occurs at the late 1NC Pentecost. We can take this further - all the way - as follows...

The 1st group is appointed/installed to rule over the 1NCs at 1NC first fruits/the 1NC Pentecost
The 2nd group is appointed/installed to rule over the 1NCs at the 2nd occurrence of a 1NC first fruits/Pentecost which may be the 1NC first fruits/the late 1NC Pentecost or may be 2nd 1NC first fruits/the 2nd 1NC Pentecost
The 3rd group is appointed/installed to rule over the 1NCs at the 3rd occurrence of a 1NC first fruits/Pentecost which may be the 1NC first fruits/the late 1NC Pentecost or may be 2nd 1NC first fruits/the 2nd 1NC Pentecost
The 4th group is appointed/installed to rule over the 1NCs at 2nd 1NC first fruits/the late 2nd 1NC Pentecost

The 1st group is appointed/installed to rule over the 2NCs at 2NC first fruits/the 2NC Pentecost
The 2nd group is appointed/installed to rule over the 2NCs at late 2NC first fruits/the late 2NC Pentecost
The 3rd group is appointed/installed to rule over the 2NCs at late 2NC first fruits/the late late 2NC Pentecost

The 1st group is appointed/installed as priests over non adamics at Zoar first fruits/The Zoar Pentecost
The 2nd group is appointed/installed as priests over the non adamics at late Zoar first fruits/The late Zoar Pentecost.
The 3rd group is appointed/installed as priests over the non adamics at late Zoar first fruits/The late late Zoar Pentecost.

Generally: the first appointment over a particular group of people occurs at the first date for a festival, and the 2nd appointment over that group occurs at the 2nd possible date for said festival.

The 2nd presence wing of the 3rd Holy Spirit was married on 2015Iyyar20 (a 2nd marital appointment) and so joins their installation as Aaron to the 1NC reserves subject to the Kingdom/Watchtower 1NC Alienation Times from 2008Tammuz9 (a 2nd appointment after the 2nd Holy Spirit) - 2015Tammuz9 and over the 2NCs but subject to the Kingdom/Watchtower 2NC Alienation Times from 2008Tebbeth21 (a 2nd appointment after the 2nd Holy Spirit, 2008Heshvan2 was not 2nd 2NC first fruits because 2008Heshvan was a Sabbath month) - 2015Tebbeth21. However the 3rd Holy Spirit must then be appointed as Aaron to Zoar at some point.
FDS4 was first appointed/installed to rule over the 2NCs on 1999Tishri2/Chislev21 (2NC first fruits/the late 2NC Pentecost - 1999Heshvan was a Sabbath month). Then a 2nd time on 2015Heshvan2/Chislev21 (2nd 2NC first fruits/the 2nd 2NC Pentecost). The installation is on the same day as the first installation over the 2NCs. But that was a late version of 1999Heshvan21 - So perhaps it does not use up Chislev21?
FDS4 was appointed/installed  to FEED the 1NCs on 1998Heshvan2/Chislev21 (2nd after FDS3) but failed the ruling test due to HyperOs and was never appointed/installed to rule over the 1NCs
Laodicea was appointed/installed to feed the 1NCs on 2003Chislev2/Shebat21 (2003Tebbeth was a Sabbath month) (3rd after FDS3 and FDS4, hence at 3rd 2NC first fruits/the 3rd 2NC Pentecost).
Laodicea passed their rulership test are were appointed/installed to rule over the 1NCs 3 years of the fundamental pattern of U42 later on 2007Iyyar17/Tammuz6 (2007Ab was a Sabbath month) (2nd 1NC first fruits/the 2nd 1NC Pentecost - because FDS4 was appointed/installed to feed the 1NCs but failed to be appointed/installed to rule over them).

Elijah4 was appointed/installed to feed the 1NCs on 1998Heshvan2/Chislev21 (2nd after FDS3) after their 3 accountable Passover denials on 1996Nisan14/1997Nisan14/1998Nisan14 and after FDS3 fell over the saints on 1998Tishri27
3 years of the fundamental pattern of U42 later, Elijah4 was NOT appointed/installed to rule as sacred king over the 1NCs on 2002Iyyar21/Tammuz10 (2nd after FDS3) having failed the test due to HyperOs

Elijah4 was appointed/installed to feed the 2NCs on 1996Nisan18/Sivan7 (1st) after being thrown out of the Watchtower on 1995Adar11.
3 years of the fundamental pattern of U42 later, Elijah4 was appointed/installed to rule as sacred king over the 2NCs on 1999Tishri2/Chislev21 before HyperOs.

Non Adamic and Kingdom Appointments/Installations

Passover Date Appointment/Installation Zoar First fruits/Pentecost Kingship To rule over Church
2012Sivan14 2012Sivan16/Ab5 1st Sacred Non adamic Abraham Abrahamic LWs (Zoar)
2012Ab14 2012Ab16/Tishri5 (2012Tammuz16 is the Sabbath) 3rd Sacred Non adamic Abraham Abrahamic Laodicea
2015Tebbeth14 2015Tebbeth16/Adar5 8th Sacred Non adamic Abraham Isaaic LWs (Zoar)
2015Shebat14 2015Shebat16/2016Nisan5 9th Sacred Non adamic Isaac Isaaic LWs (Zoar)
2019Tishri14 2019Tishri16/Chislev5 NOPE 5th Sacred Non adamic Abraham Reappointed Laodicea
2020Tishri14 2020Tishri16/Chislev5 5th Sacred Non adamic Abraham non adamic Sodom
           
2022Tishri14 2022Tishri16/Chislev5 (weekly Sabbaths) NOPE 5th Caesar    
2022Shebat14 2022Shebat16/2023Nisan5 9th Caesar Cain Kingdom of God under Jesus
2022Shebat14 2022Shebat16/2023Nisan11 11th 1NC Caesar Adam Kingdom of God under Jesus
2022Adar14 2022Adar16/2023Iyyar5 10th Caesar Non adamic Abraham Kingdom of God under Jesus
2023Nisan14 2023Nisan16/Sivan5 11th Caesar Non adamic Isaac Kingdom of God under Jesus
2023Chislev14 2023Chislev16/Shebat5 1st Isaaic Caesar Cain Kingdom of God under Jehovah
2023Chislev14 2023Chislev16/Shebat5 9th 1NC Caesar Adam Kingdom of God under Jehovah
2023Tebbeth14 2023Tebbeth16/Adar5 2nd Isaaic Caesar Non adamic Abraham Kingdom of God under Jehovah
2024Iyyar14 2024Iyyar16/Tammuz5 6th Isaaic Caesar Non adamic Isaac Kingdom of God under Jehovah

At last we fully understand what a Pentecost is. God is plainly Swiss-German!