an English question
"I am out of the office until 08.10.15." It means I will be back the office on 08.10.15? Or 09.10.15?

Question

Answer

It means that you'll be returning on the morning of  08.10.15. That is your first day back in the office. That's clear.

What is unclear, though, is what date 08.10.15 actually is.  The 8th October or August 10th?  It all depends on the convention used in the country in question.

Answer

It means your back to office 9th