[Spare_account]

Somewhere else in the thread, it was suggested that these 'late slips' might be useful for proving to one's employer why they were late to work.

Is this the only use for them?

I am reminded, once again, how lucky I am to have been employed by people who trust me.

[tmtvl]

The only use for a late slip is to prove to someone (doesn't necessarily have to be an employer) that you were late due to no fault of your own.