calculate minutes a delivery is late

Smartsheet currently is unable to calculate time. However, depending on your setup and overall requirements, some basic formulas in helper columns can be used.

Will the expected and actual times overlap into another day? Do you want it displayed in just minutes? What format are you using for time (12 or 24 hour clock/colon or no colon/am vs pm/etc..)? Are you able to post some screenshots with dummy data manually entered to show what you want the final solution to display?