Grails - jQuery datepicker error when editing

I had my jQuery datepicker working and saving the date the way it should several days ago. But now I have an error when I'm trying to edit an entry. I think it has to do with the way Grails import the date from DB to form. Please pinpoint me to the right direction. I've used a custom taglib.

import org.springframework.web.servlet.support.RequestContextUtils as RCU

/**
 * 
 * A datepicker based on JQuery datepicker (http://jqueryui.com/datepicker/) and (mostly) compatible with the Grails framework
 * 
 * Version 0.1 - 27/02/2014
 * 
 * Supported attributes:
 *  - name      : will be used as name and if for the actual input field
 *  - value     : default value
 *  - option    : options to pass to datepicker {key1: value1, key2: value2, ...}. See API: http://api.jqueryui.com/datepicker/
 *  - locale    : locale to be used. If not passed, it will take the grails session's locale (first two letters). jquery.datepicker's locale files should be available to your app: https://github.com/jquery/jquery-ui/tree/master/ui/i18n
 *  - class     : HTML classes to apply to the visible field
 *  - required  : HTML required attribute
 * 
 * Setup:
 *  - make sure JQuery-UI and JQuery are installed
 *  - put this class in your grails-app/tablib folder
 * 
 * Example: 
 *  <g:datepickerUI name="myDate" required="true" value="${myDomainClass?.myDate?:new Date()}" options="{minDate:'0', maxDate:'+10Y'}" class="form-control"/>
 * 
 * 
 * Tested with:
 *  - JQuery-1.11.1
 *  - JQueryUI-1.11.3 
 *  - Grails 2.4.4
 */


//Renders the content from DB to GSP preserving newlines
class JQueryUITagLib {
    def datepickerUI = { attrs ->
        def name = attrs['name']?:'myDateField'
        def value = attrs['value']
        def options = attrs['options']?:'{}' //{key1: value1, key2: value2, ...}
        def locale = attrs['locale']?:RCU.getLocale(request).toString().substring(0,2)
        def htmlClass = attrs['class']
        def htmlRequired = attrs['required']?"required = 'true'":''
        def placeholder = attrs['placeholder']?:''

        def namePicker = name+"_picker";
        def nameDay = name+"_day";
        def nameMonth = name+"_month";
        def nameYear = name+"_year";

        def c = null
        def day;
        def month;
        def year;
        if(value!=null){
            if(value instanceof Calendar) {
                c = value
            } else {
                c = new GregorianCalendar();
                c.setTime(value)
            }
            day = c.get(GregorianCalendar.DAY_OF_MONTH)
            month = c.get(GregorianCalendar.MONTH)+1
            year = c.get(GregorianCalendar.YEAR)
        }

        out << "\
        <input type='text' id='${namePicker}' name='${namePicker}' placeholder='${placeholder}' class='${htmlClass}' ${htmlRequired} style='position: relative; z-index:100;'/>\
        \
        \
        <input type='hidden' id='${name}' name='${name}' value='date.struct' />\
        \
        <input type='hidden' id='${nameDay}' name='${nameDay}' value='${day}' />\
        <input type='hidden' id='${nameMonth}' name='${nameMonth}' value='${month}' />\
        <input type='hidden' id='${nameYear}' name='${nameYear}' value='${year}' />\
        "

        out << "\
         <script type='text/javascript'>\
         \$(document).ready(function(){\n\
             \$('#${namePicker}').datepicker(${options});\n\
             \$('#${namePicker}').datepicker('option',\$.datepicker.regional['${locale}']);\n\
             \$('#${namePicker}').on('change', function(){\n\
                 selDate = \$('#${namePicker}').datepicker('getDate');\n\
                 \$('#${nameDay}').val(selDate?selDate.getDate():null);\n\
                 \$('#${nameMonth}').val(selDate?selDate.getMonth()+1:null);\n\
                 \$('#${nameYear}').val(selDate?selDate.getFullYear():null);\n\
             });\n\
             var dateFormat = \$('#${namePicker}').datepicker( 'option', 'dateFormat');\n\
         "
        // If a value is specified it overrides the default date
        if(attrs['value']){
            out << "\
                 //Set date from value\n\
                 \$('#${namePicker}').datepicker('option', 'defaultDate',new Date(${year},${month-1},${day}));\n\
                 "
        }
        out << "\
             var defaultDate = \$('#${namePicker}').datepicker( 'option', 'defaultDate');\n\
             //Set default date\n\
             \$('#${namePicker}').val(\$.datepicker.formatDate(dateFormat, defaultDate))\n\
         });\n\
         </script>\
         \
         "
    }
}

And this is the error I get.

Class
groovy.lang.MissingMethodException
Message
No signature of method: java.util.GregorianCalendar.setTime() is applicable for argument types: (java.lang.String) values: [02-Mar-2006] Possible solutions: setTime(java.util.Date), getTime(), clearTime(), setTimeZone(java.util.TimeZone), setTimeZone(java.util.TimeZone), getAt(java.lang.String

)

Error because when you init datePicker on your gsp: you enter in value String, not Date. So recheck it and try value="${new Date()}" if it throw error again ping me in comment, please.

UPD. More in comments