"Invalid date format" error when releasing a version from browse project page

steps to reproduce

1. in JIRA Admin > System > Look and Feel set the Day/Month/Year Format to a format using spaces, e.g. 'dd MMM yy'
2. go to the Versions list of any projects, and click Release for a Version;
3. select the release date using the calendar dropdown - it'll be displayed in the default format, e.g. '27/Feb/15'
4. click Release and see the error thrown:

   java.lang.IllegalArgumentException: Invalid format: "27 Feb 15" is malformed at " Feb 15"
   java.lang.IllegalArgumentException: Invalid format: "27 Feb 15" is malformed at " Feb 15"
   	at org.joda.time.format.DateTimeFormatter.parseLocalDateTime(DateTimeFormatter.java:828)
   	at com.atlassian.jira.datetime.JodaDateTimeFormatter.parse(JodaDateTimeFormatter.java:45)
   	at com.atlassian.jira.datetime.DateTimeDatePickerFormatter.parse(DateTimeDatePickerFormatter.java:34)
   	at com.atlassian.jira.datetime.DateTimeFormatterImpl.parse(DateTimeFormatterImpl.java:54)
   	at com.atlassian.jira.util.DateFieldFormatImpl.parseDatePicker(DateFieldFormatImpl.java:42)
   	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   	at java.lang.reflect.Method.invoke(Method.java:483)
   	at com.atlassian.plugin.osgi.hostcomponents.impl.DefaultComponentRegistrar$ContextClassLoaderSettingInvocationHandler.invoke(DefaultComponentRegistrar.java:134)
   	at com.sun.proxy.$Proxy366.parseDatePicker(Unknown Source)
   	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   	at java.lang.reflect.Method.invoke(Method.java:483)
   	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
   	at org.springframework.osgi.service.importer.support.internal.aop.ServiceInvoker.doInvoke(ServiceInvoker.java:58)
   	at org.springframework.osgi.service.importer.support.internal.aop.ServiceInvoker.invoke(ServiceInvoker.java:62)
   	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
   	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
   	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
   	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
   	at org.springframework.osgi.service.util.internal.aop.ServiceTCCLInterceptor.invokeUnprivileged(ServiceTCCLInterceptor.java:56)

workaround

Revert the Day/Month/Year Format to the default settings. Or, release the version from project's administration page for version.