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Editorial Team
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Asked: 2026-05-25T21:01:06+00:00

When comparing date objects in Javascript I found that even comparing the same date

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When comparing date objects in Javascript I found that even comparing the same date does not return true.

 var startDate1 = new Date("02/10/2012");
 var startDate2 = new Date("01/10/2012");
 var startDate3 = new Date("01/10/2012");
 alert(startDate1>startDate2); // true
 alert(startDate2==startDate3); //false

How could I compare the equality of these dates? I am interested in utilizing the native Date object of JS and not any third party libraries since its not appropriate to use a third party JS just to compare the dates.

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1 Answer

  1. Editorial Team

    That is because in the second case, the actual date objects are compared, and two objects are never equal to each other. Coerce them to number:

     alert( +startDate2 == +startDate3 ); // true

    If you want a more explicity conversion to number, use either:

     alert( startDate2.getTime() == startDate3.getTime() ); // true

    or

     alert( Number(startDate2) == Number(startDate3) ); // true

    Oh, a reference to the spec: §11.9.3 The Abstract Equality Comparison Algorithm which basically says when comparing objects, obj1 == obj2 is true only if they refer to the same object, otherwise the result is false.

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