Pop up alert when time is 12pm

[samuel_lopez]

How to automatic pop up an alert when time is 12 pm using javascript.

[Jacques1]

12 p. m. in what time zone? The user's zone? The server's zone? Some other zone?

 

Assuming the user's local time: Get the difference in milliseconds between the target time and the current time, then set a timeout for this difference.

popUpTime = new Date();
popUpTime.setHours(12);
popUpTime.setMinutes(0);
popUpTime.setSeconds(0);
popUpTime.setMilliseconds(0);

now = new Date();

setTimeout(function () {
    alert("Oh hai.");
}, popUpTime - now);

I hope you're not actually using an alert(), because that's one of the most annoying misfeatures ever invented.