Templates apply on a repeating basis for the span of time to which they are assigned to each user. Therefore, you can create a 30 day-long schedule that repeats, and assign it to each user for as long as that template applies. However, due to the varying lengths of months, the template will not align with each calendar month. If you require the template to apply to a calendar month, you can assign a new template for each month, using mass edit functionality.