Are You Required to Exercise Extended Visitation if You Can't Get Time Off of Work

My question involves a child custody case from the State of: Maine

I am the non-custodial parent. My agreement says "Holidays and school vacations shall be divided as follows: each party is entitled to one of February and April school vacation weeks with the children." Am I required to take the children one of these weeks? I want to, but am unable to get vacation time from work. My ex wife is a teacher, so she has the same vacation schedule as the children. The primary residence of the children is with her.

The agreement also states the parties shall have children for two weeks of vacation each summer. I only get 1 week of vacation from work, so am I required to take them for two weeks?

You're not required to exercise any of your visitation.