Translation of backbone in Spanish

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.
There are changes in regulations for people who wish to travel to Eastern Europe. This is advantageous. In the U.S., as in every country in the world, there are positive and negative changes.
If you want to write again in Spanish, just do it. I have much to do at the moment, again and again... Sometimes it happens that I must work at night until the early hours of the morning.