goog.provide('moose.test'); goog.require('goog.array'); goog.require('goog.date'); moose.test = function() { var d1 = new goog.date.Date(2010, 12, 24); var d2 = new goog.date.Date(2011, 1, 6); var d3 = new goog.date.Date(2010, 12, 30); var singleDateObject = new goog.date.DateTime(2011, 1, 12, 13, 56, 57); var dates = [d1, d2, d3]; var isIn = goog.array.find(dates, goog.partial(goog.date.isSameDay, singleDateObject)); var isIt = goog.array.findIndex(dates, function(range) { return goog.date.isSameDay(range, singleDateObject); }); console.log(isIn); console.log(isIt); };