How to send SMS reminders for mobile Internet traffic?

The default reminder is weekly or monthly, and the user can change it to daily reminder or unsubscribe. Weekly Reminder: Every Monday morning, the system will notify users by text message of the accumulated traffic usage and charged traffic of the current month (the deadline is 24:00 the day before). Monthly traffic reminder: On the morning of the first day of each month, you will be reminded of the traffic consumed in the previous month. If the first day of the month overlaps with a Monday, only one text message is sent. Daily reminder: In the morning after the user generates Internet data traffic, a text message will be sent to remind the user of the traffic consumed the previous day.