Is the date in the general book solar or lunar? Especially when it comes to seasons.

If there is no date in general books, it usually refers to the solar calendar, which is the Gregorian calendar.

When it comes to solar terms, farming season and some proverbs, it's usually the lunar calendar. Such as "dressing indiscriminately in February and August"

Some traditional festivals refer to the lunar calendar, such as February 2nd, March 3rd, Mid-Autumn Festival, Spring Festival, Lantern Festival, Queqiao Festival and Ghost Festival. This is because these are the Millennium traditional festivals in China, and there was no Gregorian calendar at that time. The Gregorian calendar was introduced into China only in modern times.