Prompted by this question:
I understand in this instance, the usage of the statues of the Buddha himself makes it seem that this has something to do with Buddhism, but it really doesn't - it's simply a use of the Buddha image by Thai people to exemplify supposed qualities of people born on specific days of the week; nothing to do with Buddhism as it is taught in Thailand. E.g., a person born on the day of the Buddha holding the alms bowl is said to be blessed with affluence. Obviously, the person asking the question may not be aware that this is not actually a Buddhist practice, but how should we deal with such questions?
For example, if a monastery runs a public food court; should we allow questions about the running of the food court? Or a beauty pageant? What about if they teach traditional Thai massage? Or parade a Buddha image around the city to bring rain?
Basically, what should we do with questions that don't have a Buddhist answer? If the correct answer to a question lies outside of Buddhism, is the question off topic even if it is an accepted practice of certain Buddhists?