Verb conjugation of "verlängern" in German

Please take into account, that on May 10 and 11 there are holidays in the United States and that we do not work on Saturday. This will leave only the 15th, 16th and 17th for a company visit.
I will answer your mail during the weekend. Please translate the same text to Hungarian. I think it is easier to write. We can do the same with Spanish. Just note that the context needs to stay the same.
In school, we now are learning the grammar part, more specifically, the participles and so on. I understand it at all, but the conjugations, boy they are tough. A lot of patience is needed.