Aren't you allowed so many days in term time ?
Think it is best if you can avoid taking them out of school during term for all reasons as already stated. As long as no longer than 5 school days (missing probably 1 lesson of importance in their curriculum) then acceptable, any longer to me is not.
'Tis sad though that holidays abroad are loaded during peak holiday times, so why not consider the UK .. wonderful place.
Kids love it whether in Cornwall, Scotland, Wales as against Benidorme, Grand Canaria or Disney Land, just the parents that prefer the sun.