Translation of ausrechnen

Work was performed only in June, July, August and September. In October and November, Erik has been waiting for Katja's visit and Sabine was on maternal leave after Christmas and New Year.
I've also looked at the interface, and found it a good idea to include the colloquial option. Would it be very complicated to add the most important regional check box, like Spain, South America or Central America?
I understand your English, it's not bad at all. Yes, the English vocabulary is much larger than the German. The more you might spend time using the language, the better your vocabulary knowledge will become.