How can I do this in rails active record¿?
find all models that match (created_at + 100 days between this month)
Edit: Ok, Sorry for not be precise this what
ActiveRecord can build a query using a BETWEEN when it accepts a Range. This sounds like it might be more what you are looking for.
ActiveRecord
BETWEEN
Range
YourModel.where(created_at: 100.days.ago..100.days.from_now)
It always seems a little simpler to do this than using >= <= in the query
>=
<=