This is the 702nd most frequent Czech word.
týdnech
"Weeks" (in the locative or instrumental case).
Here, 'týdnech' is used as a plural noun in the locative case, indicating the time period during which something happened.
V posledních týdnech se počasí velmi změnilo.
In the last weeks, the weather has changed significantly.
In this example, 'týdnech' is used in the locative case to refer to the holiday weeks in which the family trips are planned.
O prázdninových týdnech plánujeme rodinné výlety.
During the holiday weeks, we plan family trips.
Here, 'týdnech' again is a plural noun in the locative case, showing the specific weeks during which the meetings occur.