Dear Sir/Madam,
My name is ________ (name) and I am working as _______ (designation) in your company.
I am writing this email to request you that I am willing to take half day off from the work on __/__/_____ (date) as ________ (mention reason – health issues/ headache/ appointment with doctor/ any other).
I write this to seek your permission to kindly approve my request at the earliest and I shall be highly obliged for your kind support.
Thanking you,
___________ (Name),
___________ (Designation),
___________ (Contact details)