Valid If for Calendar Availability?

[Jason_Stetler]

Hello,

I am having a difficult time trying to structure a Valid If statement that will help me out with limiting which users can be selected for events on a calendar that references a second calendar with the same potential user’s unavailability (posted as events). My goal is to make certain users on a list error as unavailable if their schedule is blocked off on the referenced crew calendar.

Here is what I am working with right now, and I feel close, but am just not sure what to do:
The following is what I have written in the Valid If section of the column [PIC] on a google calendar table where:
StreamFleet Crew = The referenced calendar that holds the crew schedules
Start and End are the date/times of the event postings
PIC = a crew member selection when creating a calendar event (Enum - Ref - Crew table)
Creator = references the creator email of events on the StreamFleet Crew schedule calendar

AND(
ISBLANK(
FILTER(“StreamFleet Crew”, AND(
([_THISROW].[Start] >= [Start]),
([_THISROW].[Start]<= [End]),

([_THISROW].[PIC] <> [Creator])

)
)

-LIST([_THISROW])
) ,

[_THISROW].[Start] >= TODAY()
)
AND(
ISBLANK(
FILTER(“StreamFleet Crew”, AND(
([_THISROW].[End] <= [End]),
([_THISROW].[End]>= [Start]),

([_THISROW].[PIC] <> [Creator])
)
)

-LIST([_THISROW])
) ,

[_THISROW].[End] >= TODAY()
)

Any and all help is very much appreciated!