There is a solution in StackOverflow: /\* use a function for the exact format desired... \*/ function ISODateString(d){ function pad(n){return n<10 ? '0'+n : n} return d.getUTCFullYear()+'-' + pad(d.getUTCMonth()+1)+'-' + pad(d.getUTCDate())+'T' + pad(d.getUTCHours())+':' + pad(d.getUTCMinutes())+':' + pad(d.getUTCSeconds())+'Z'} var d = new Date(); print(ISODateString(d)); // prints something like 2009-09-28T19:03:12Z ```But there is already a function for this: toISOString, it came with ecmascript 5. [Unfortunately, not all browsers support this](http://kangax.github.com/es5-compat-table/ "See the best comparision for ecmascript 5 support"), to solve this problem, we can provide our own prototype function for Date if it doesn't exist: if (!