It would require 2 of 2 multi sig key for full lock or 2 of 3 multi sig key in case you want to spend it suddenly without the limitation. Many services provide limits on spending over a period of time. Greenaddress.it has 2 of 2 multisig and they control one, you control one. Without their signature, you won't be able to spend it.
I think its better to learn to control yourself in order to save money rather than have some forced lock on your wallet. You may eventually be on a situation where you really need the money and you are stuck with a lock for X time. Bitcoin core can allow you to get your stuff encrypted so you need to put your pass everytime you want to spend, this helps.
Unless I understand it wrongly, OP is talking about setting a limit on the frequency of transactions.
where we can save bitcoin, and lock it,?
and is taken once a month
Anyway, if I were to need a spending limit, I would go for a service which has 2 of 3 multisig. That way, I have two key on my side and can withdraw funds without limitation. One of the keys can be placed away from the main key and used only in emergency.
