How many days after Buddhist cremation?

After cremation, they can be buried immediately. This is the meaning of being buried. If you have enough conditions, you can put it in a temple and listen to the Buddha name every day. Generally, it can be buried after 7749 days. If you don't have enough conditions, you can be cremated and buried. In fact, the key here is not the ashes, because once a person dies, the body is like a container, and it is no longer important. What is important is how to make the gods of the deceased (we can think of them as "souls" superficially) be blessed by the Buddha within 7749 days (for example, future generations can recite the Tripitaka to the deceased to ensure that they can enter Buddhist countries such as Sanshan Island and even the western paradise). That's all that matters.