A multivisa for a holiday in Greece (that is, a tourist multivisa) is usually obtained for half a year with the 90/180 action corridor, that is, with the total duration of stay in the Schengen zone not more than three months (90 days) from any half year (180 days) -participants of the Schengen agreement. Accordingly, you need to focus on the number of days spent in the territory of the Schengen area in the current half of the year.

By the way, if you, of course, are interested in further obtaining a new multivisa, by the time it ends, it is highly desirable that the number of days spent in Greece is greater. It is believed that Germany is the most scrupulous to the rules for the implementation of the Schengen agreement.