數ㄕㄨˇshǔ伏ㄈㄨˊfú

伏，俗稱自夏至後第三庚日起，每十日為一伏，有三伏，共三十日，為夏季最熱的時間。數伏指進入伏日或伏日開始。

英same as 三伏天[san1 fu2 tian1], three periods forming the hottest periods of summer, from mid-July to mid-August, namely: 初伏 (mid-July), 中伏 (late July to early August), 末伏 (mid-August)

德die drei 10-Tage Periode in der heißen Saison