IE8 & IE7 JavaScript Date NaN From String Error

When trying to create a JavaScript Date object from a string I was getting an NaN error in IE7 and IE8. My JavaScript worked in all the other browsers I was testing in. I was writing the script to figure out future dates based on the date the user selected. Issue is that IE7 and 8 don’t handle strings as well as real browsers. I was able to fix the error by using date.setFullYear instead of expecting the browser to handle it. Found a great function in to handle this.


function parseISO8601(dateStringInRange) {
	var isoExp = /^\s*(\d{4})-(\d\d)-(\d\d)\s*$/,
		date = new Date(NaN), month,
		parts = isoExp.exec(dateStringInRange);

	if(parts) {
		month = +parts[2];
		date.setFullYear(parts[1], month - 1, parts[3]);
		if(month != date.getMonth() + 1) {
	return date;

You can check out my reduced test case.

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