“入伏第一天”的英文如何表达？

first day of the dog days

伏天是按照中国农历算法，英语中没有，dog days指夏天最热的几个星期，和‘伏天’大致对应。

The first day of the hot season according to Chinese lunar calendar, which is the hottest period in summer and is devided into 3 ten-day parts.

the first day of the hottest days in a year,'fu'

beginning of the hottest part of the summer