"Day-rest" is a term used to describe a break or relaxation period during the day. However, there are multiple alternative synonyms that can be used in place of this term.
One alternative is "siesta," which is commonly used in Spanish-speaking countries to describe a midday nap or rest. Another option is "break," which can refer to a short period of time away from work or other responsibilities. "Interlude" and "respite" are also suitable synonyms for day-rest, as they both imply a temporary break from activity. Finally, "recess" could be used to describe a break in the middle of a school day.
Overall, there are many different words that can convey the concept of taking a break or resting during the day.