翻译成英文，假条

I have a very important physical examination every year.It's hard to change the date because it's not easy for me to get this appointment.
And my reservation is Decemeber 15th this year ,I'm sure I'll come back on Decemeber 13th.
Hope you to understand and approve of my leave.

I do my health checkup annually, this checkup is vert important and I had to book in advance, my booking this year is on the 15th of Dec.
i have decided to come back on 13th, please approve my leave.

Each year, I have to do the health check in my home country.
It is very important, and hard to make a reservation, so I can not change it.

This year it will be on the Dec.15th, and I have to go back no less than Dec.13th.

Please give me permission for leave.

I take a physical examination annually at home.
This physical examination is vary important, and it's hard to reserve,can't change date verily.
The date is on the 15