typescript / date
date
This domain publishes 1 contract, settling 43 named edge cases. Taking it puts 7 075 bytes of TypeScript in your project, and it imports nothing.
add
Add a duration to a Date and get a new Date back, in UTC, without mutating the input, or null when the call cannot be answered exactly - with a named reason available beside it for a caller who needs to know which refusal it was.