I would like to limit users to selecting only the first and third Monday of each month. We have a volunteer intake only on these days, so I want to limit incorrect date selections as much as possible.

I'm not a js coder, but have managed to adapt some code I found online to allow the first *or third* Monday of each month, but I can't work out how to allow both of them.

Here's the code I have for the first Monday:

```
var firstMonday = new Date(date);
var mondays=0;
firstMonday.setDate(1);

while (mondays < 1) {
    firstMonday.setDate(firstMonday.getDate() + 1);
    if (firstMonday.getDay() == 1) {
        mondays++;
    }
}
var result = date.getDate() != firstMonday.getDate();

```