![]() ![]() To put it all together, here’s a simple little page that has both JavaScript code pieces displayed: ĭaysLeft = Math. ![]() Whenever you want to actually include that value on the page, simply add a single line of JavaScript within the HTML code: document.write(daysLeft) ![]() Finally, we use the mathematical floor function to make sure we don’t get weird values like 23.434233 days or similar, as a convenience. Notice that since we’re actually working in milliseconds and we want days, we need to divide by 1000 to get seconds, then divide by 60 (to get minutes), 60 again (to get hours) and then 24 (to get days). This JavaScript code snippet, which I’d put in the HEAD of my document, calculates the number of days left until the target date and saves it in the variable daysLeft. Anyway, let’s see some code! ĭaysLeft = Math.floor(((targetEpoch - todayEpoch) / (60*60*24)) / 1000) For convenience, it’s 1 Jan, 1970 on most systems, but if you think about it you’ll realize that it doesn’t matter what date the epoch time starts with, as long as it’s consistent across both values. I know theres a good amount of tutorials out there about building a timer, but from experience, whenever I use examples I dont really learn. Viewed 2k times 2 Im trying to code my own timer from scratch. Ask Question Asked 3 years, 3 months ago. Then we want to work with what us Unix types call the “epoch time” which is the number of milliseconds since a fixed point in the past. First program: javascript countdown timer. Want to have a date object with 28 February, 2005 as the specified date? Use new Date(“28 February, 2005”) and it’ll work just fine. You get the current date in JavaScript with new Date(), and it turns out that if you specify a date in the parens, it instantiates (creates) a new object with the specified date, rather than today. If you need more advanced object-oriented programming features in JavaScript, you can use JavaScript++ to create a JavaScript class.īut, really, this task is even easier than that, because all we need to do is set a specific target date in the future, get the current date, then calculate the amount of time between them and divide it out so that we end up with days as the value. The key is to realize that JavaScript is a so-called object oriented programming language and that it has a specific date object with “methods” that let you set and extract specific values. This is an obvious situation where JavaScript is going to be your friend, and it turns out that this is a straightforward application of JavaScript so it should be fairly easy. ![]()
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