Last tested: Mar 19, 2021
In our docs here, https://docs.looker.com/reference/view-params/sql_trigger_value , we give you sql for how you can run a schedule once per day at any given hour.
If you run that sql in SQL runner or any database console, you'll see that it returns 5 digits.
Those 5 digits are not unix time. Those 5 digits are the number of times that timeframe (X hour) has been passed since the start of unix time. For instance, if you get 18705 returned, it means 18705 days have passed since 1970-01-01