This is such a fantastic & useful tip, @Kuovonne!!
Thank you for sharing these excellent formulas, and also for reminding all of us about the incredibly useful Unix millisecond timestamp. 
On a somewhat related note to @kuovonne’s tip:
If you want to lookup a field from another table, but you only want to lookup data from whichever linked record contains the earliest/latest date, you can start with @kuovonne’s formulas in the linked table, and then use the extra tricks that I discuss in the BuiltOnAir podcast episode below.
Hope this helps! If you’d like to hire the best Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld