Look at the school's calendar, and plan vacations around it.
I know this is just for Kindergarten and 2nd grade kids.
But still, they will be missing 1 week of school.
And, per the curriculum, you do not know what they will be missing in school. There is also, homework, in addition to the in-class class work, that kids do. And so, your kids WILL need to catch up on and do, all the work they missed. Before they return to school.
And it depends, on what part of the year they will be missing school. If it is the beginning of the school year, they won't have time to adjust to their new classroom/teacher/and routines. Just as an example.
I work at my kids school. There are many kids, of all grades, that miss school, due to family trips. And the Teachers, are not fans of this habit. The kids who are students, miss out on a lot of learning, and they also have a lot to catch up on. IF a parent, ahead of time... gets their child's school work to bring home... then the child will need to do it while on the trip. Or before they return to school. If not, then the child will have to do it all, once they return to school... PLUS also doing, what is currently being taught. So, that is double, the work. For example.
Then, there are some kids, who are absent a lot, due to being out sick... and also due to family trips. And in some of these cases, depending on how many absences they have accrued... I know a couple of kids that will not, be going on to the next grade. Because they were absent too many times during the school year.
An absence, is an absence. And it is tallied during the school year.
If you work with the Teacher, and talk to her/him, AND get your child's school work/homework/in-class work AHEAD of time... and have your child do it while you are away... then that will help.
No matter what, school work/homework/in-class work, DOES need to be, caught up on, and, completed. Just as it would be for any child. If a child does not complete all work, then that is noted.
There are some kids who took trips during the school year in my kids' classes... and the other kids do wonder "do they have to do their work, too? Its not fair if they don't just because they took a trip...."
At my kids' school, Kindergarten and 2nd graders, do get homework. Everyday. In varying degrees.