Madam, this is a quite common method to harass the petitioner the maintenance cases.
The husband often refuses to make payment for months together warranting the petitioner to file execution case which you can also file if he defaults to make payment for one month or more.
In the execution case the W/A can be issued by court if the husband continues to default in making the arrears maintenance. Once he makes the payment then the court does not proceed against it.
So in your case you should feel lucky f your husband continue t make the maintenance payment on every month even if the same is after 10th of each month. There is no illegality in it.