Default expiration format in other than days

[norkunas]

Description There is no way to configure expiration in another format than days. I've found that spatie/url-signer supports providing expiration as DateTime instance.

Example N/A

[alanpoulain]

You can specify a DateTime when you sign the URL. Would it be really useful to have it for the default expiration too?

[norkunas]

Then it would not require me to pass it everywhere :) also it's a little bit unfortunate that it's not possible to provide immutable datetime :)