New Wizard of the month on JKR website and her amasing math skills ;)

[Pamela Rosen]

No: HPFGUIDX 177618

Geoff:

We have already calculated that the events of the epilogue occur in
the summer of 2017 when Harry is 27.

Pam:
My math is worse than anyone I know, but I think Harry would be 37 if he was born in 1980, was almost eighteen when DH ended, and then a further 19 years had passed.  My son is eight and he was born in 1998, and he made a big deal about being exactly the same age as Teddy Lupin.