Datepicker Keyboard Shortcuts Navigate Incorrectly with Bounded Multi-Month Options Set

Version Tested: jQuery UI 1.10.3; OS Tested: Windows 7; Browsers Tested: IE, Firefox, Chrome (bug most likely impacts all browsers and platforms)

When defining a Datepicker object with multiple months (numberOfMonths > 1) and fixed bounds (minDate and maxDate are defined), the keyboard shortcuts navigate improperly when the focus goes into the second month displayed. A bug exists in the jQuery UI Datepicker codebase which causes the focus to incorrectly jump back into the first month upon the next keyboard command.

To re-create the issue, create a new two-month Datepicker object with minimum and maximum dates that define a 45-day window around the current/default date. For example, if today's date is August 4, a minimum date of August 1 and maximum date of September 15 would produce a Datepicker object with this issue. Once defined, use the keyboard commands (e.g. Ctrl+Right) to navigate forward through the calendar. When the focus gets to the second month displayed, the script incorrectly jumps back into the first month displayed, which mistakenly makes it impossible for a keyboard user to effectively choose any date outside of the first month.

Upon further inspection of the code, the following modification appears to resolve the issue:

/* Adjust one of the date sub-fields. */

_adjustInstDate: function(inst, offset, period) {

var year = inst.selectedYear + (period === "Y" ? offset : 0),

month = inst.selectedMonth + (period === "M" ? offset : 0),

day = Math.min(inst.selectedDay, this._getDaysInMonth(year, month)) + (period === "D" ? offset : 0),

date = this._restrictMinMax(inst, this._daylightSavingAdjust(new Date(year, month, day)));

Detailed examples of the bug and fix suggestion are provided at the following URLs:

Bug Example: http://jsbin.com/edutah/6/

Fix: http://jsbin.com/edamig/1/

Fix Example: http://jsbin.com/emufuq/1/