Hi everyone! We were stumped on this for a while and couldn't find any workarounds. So here's how to extract the next date in a series of dates inside of an array or a rollup from another table.
1. Convert your dates to UNIX and wrap them up in a VALUE so that they are all fixed numbers
VALUE(DATETIME_FORMAT([date], 'x')
2. In the table where you're wanting to store & retrieve the "Next date" in a series, create a lookup of the column you just created in step 1 & chuck a filter on it that says "On or after Today"
3. Create a new formula column and retrieve the 'minimum UNIX date' with a MIN()
MIN({Your Lookup Column Name})
4. Convert step 3 back to your desired date with a DATEADD() formula
DATEADD('1/1/1970',{Your column from step 3},'seconds')
Voila, you now have the "next upcoming date" in a series of dates.
