What moon phase can you see on February 18 of the Gregorian calendar (that is, "rain" in the 24 solar terms)? Like a full moon and a new moon?

The moon phase has nothing to do with the Gregorian calendar, so the answer is uncertain.

There is a simple reason. The period of the first lunar month is 29.53 days, and 12 months is 354 days. What about a year? 365 days, the two are disproportionate. The latter will be longer 1 1 day than the former, and the moon meeting on a certain day next year will be worse 1 1 day than the previous year.

For example, this year's rain is the first quarter moon, next year is the convex moon (remnant), the year after next is the new moon, and the year after next is the convex moon (new). ...

There is a more intuitive example. When will the Spring Festival come next year? I believe the landlord, like me, doesn't know. I have to calculate or find a mother. If the Gregorian calendar can be linked to the moon, will it be so troublesome?