A missed birthday can be remedied

I was just over at The Universe in a Blog and was reminded that Harry Potters birthday was the 31st of July, ah, missed it, we totally forgot

We What! Oh no,

(Mercedes is a big Harry Potter fan, her middle name is even Hermione)

I know how to fix this

But Mercedes it's the 2nd of August now, is it safe to go back that far?

ooh

The Harry Potter wiki suggests five hours is the limit without it impacting time and the traveller seriously, oh dear