JS, Javascript, programming calendar making ideas

At the end of last year, I wrote a jquery calendar plug-in, and the idea at that time was this:

1, get the day of the week on the first day of each month.

2. How many days do you get each month? For example, 30.

Then loop for 30 days, 30 times, needless to say, add 1 to each loop, and then put each value in the td of the table.

Then get the days of last month and next month, and fill in other forms by subtracting last month and adding next month, so that a complete calendar in months will do.