What does ends midnight mean?

[animalcrossingfan2021]

I have a voucher that states end midnight 27th January. Does that mean it finishes at 12am tomorrow morning or do I have until 11.59pm tomorrow to use it?

Ends at midnight on the 27th so end of day

Midnight is actually the start of the next day so it's bad practice to write this. I'd assume 23:59 on the 27th.

Thank you thats what I thought it meant but kept overthinking it!

There's no correct answer. Both previous and following nights can apply. My experience is most people mean the final minute of the day, but it can be the first. I've had experience of a midnight deadline and it us annoying.