onSelect no vincular primera carga de tiempo

La acción onSelect del método mencionado onSelect no funciona para la primera carga. Pero cuando presiono F5 está funcionando. ¿Puede decir por qué?

  var multiDatesPickerBinding = function () { $('.button-set').buttonset(); $(".datePicker").each(function () { var target = $(this); target.datepicker({ showAnim: '', changeMonth: true, minDate: target.data('min'), changeYear: true, dateFormat: 'm/d/yy', yearRange: 'c-20:c+10' }); }); $('.enumeration').buttonset(); $.datepicker._getDate = function (inst) { var startDate = (!inst.currentYear || (inst.input && inst.input.value == '') ? null : this._daylightSavingAdjust(new Date( inst.currentYear, inst.currentMonth, inst.currentDay))); return startDate; }; $.datepicker._defaults.dateFormat = 'yy-mm-dd'; $.valHooks['multiDatesPicker'] = { get: function (elem) { return $(elem).multiDatesPicker('getDates'); } }; //, set: function (elem, v) { $(elem).multiDatesPicker('addDates', v); } }; $.valHooks['datepicker'] = { get: function (elem) { return $(elem).datepicker('getDate'); } }; //, set: function (elem, v) { $(elem).datepicker('setDate', v); } }; window.checkForCalendars = function () { $('.inline-calendar,.inline-multi-calendar').each(function () { var self = $(this); var type = 'datepicker'; var format = 'yy-mm-dd'; var target = self.data('target'); var value = self.data('value'); var args = { dateFormat: format, onSelect: function () { alert('sam'); } }; args['numberOfMonths'] = self.data('months') || 1; args['minDate'] = self.data('min'); args['maxDate'] = self.data('max'); if (self.data('multi')) { type = 'multiDatesPicker'; value = value ? value.split(',') : null; } if (target) { var rawValue = $('#' + target).val(); if (rawValue) value = $.datepicker.parseDate(format, rawValue); args.altField = '#' + target; args.altFormat = format; } self[type](args); self.data('val.type', type); if (type == "multiDatesPicker") { if (value) { self.multiDatesPicker('addDates', value); } var disallowed = self.data('disallowed'); if (disallowed) { self.multiDatesPicker('addDates', disallowed.split(','), 'avoided'); } } else { self.datepicker('setDate', value); var allowedRaw = self.data('allowed'); if (allowedRaw !== undefined) { var allowed = allowedRaw.split(','); $('.inline-calendar').datepicker('option', 'beforeShowDay', function (date) { var format = $.datepicker.formatDate('yy-mm-dd', date); return [$.inArray(format, allowed) >= 0 ? true : false, '']; }); } } self.datepicker('refresh'); }); }; window.checkForCalendars(); }; 

Llama así:

 $(document).ready(function () { multiDatesPickerBinding(); });