Timer persistence and restore

Browsing through the log file of a build including run of testsuite I found a couple of reported erros like this one:
Running org.jboss.as.test.integration.ejb.interceptor.invocationcontext.InvocationContextTestCase
22:15:56,939 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.DefaultInterceptor] (pool-2-thread-1) PostConstruct on DefaultInterceptor calledorg.jboss.as.test.integration.ejb.interceptor.invocationcontext.TimeoutBean
22:15:57,048 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.DefaultInterceptor] (EJB default - 10) PostConstruct on DefaultInterceptor calledorg.jboss.as.test.integration.ejb.interceptor.invocationcontext.TimeoutBean
22:15:57,048 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.InvocationContextChecker] (EJB default - 10) Checking timeout interceptor on: Default
22:15:57,048 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.InvocationContextChecker] (EJB default - 10) Checking timeout interceptor on: Class
22:15:57,048 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.InvocationContextChecker] (EJB default - 10) Checking timeout interceptor on: Method
22:15:57,048 INFO [org.jboss.as.test.integration.ejb.interceptor.invocationcontext.InvocationContextChecker] (EJB default - 10) Checking timeout interceptor on: Bean
22:15:57,048 ERROR [org.jboss.as.ejb3] (EJB default - 10) WFLYEJB0029: Could not restore timer from C:\Users\frank.LANGFR.000\Documents\GitHub\wildfly\testsuite\integration\basic\target\jbossas\standalone\data\timer-service-data\invocation-context.invocation-context.TimeoutBean\4f0c586c-06d3-4f35-9bf9-7bd451800482.xml: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[4,5]
Message: WFLYCTL0133: Missing required attribute(s): next-date
at org.jboss.as.controller.parsing.ParseUtils.missingRequired(ParseUtils.java:135) [wildfly-controller-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
at org.jboss.as.ejb3.timerservice.persistence.filestore.EjbTimerXmlParser_1_0.parseTimer(EjbTimerXmlParser_1_0.java:146)
at org.jboss.as.ejb3.timerservice.persistence.filestore.EjbTimerXmlParser_1_0.readElement(EjbTimerXmlParser_1_0.java:112)
at org.jboss.as.ejb3.timerservice.persistence.filestore.EjbTimerXmlParser_1_0.readElement(EjbTimerXmlParser_1_0.java:86)
at org.jboss.staxmapper.XMLMapperImpl.processNested(XMLMapperImpl.java:110) [staxmapper-1.1.0.Final.jar:1.1.0.Final]
at org.jboss.staxmapper.XMLMapperImpl.parseDocument(XMLMapperImpl.java:69) [staxmapper-1.1.0.Final.jar:1.1.0.Final]
at org.jboss.as.ejb3.timerservice.persistence.filestore.FileTimerPersistence.loadTimersFromFile(FileTimerPersistence.java:353)
at org.jboss.as.ejb3.timerservice.persistence.filestore.FileTimerPersistence.getTimers(FileTimerPersistence.java:316)
at org.jboss.as.ejb3.timerservice.persistence.filestore.FileTimerPersistence.persistTimer(FileTimerPersistence.java:198)
at org.jboss.as.ejb3.timerservice.persistence.filestore.FileTimerPersistence.persistTimer(FileTimerPersistence.java:175)
at org.jboss.as.ejb3.timerservice.TimerServiceImpl.persistTimer(TimerServiceImpl.java:611)
at org.jboss.as.ejb3.timerservice.task.TimerTask.run(TimerTask.java:193)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [rt.jar:1.8.0]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [rt.jar:1.8.0]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0]
at java.lang.Thread.run(Thread.java:744) [rt.jar:1.8.0]
at org.jboss.threads.JBossThread.run(JBossThread.java:122)
This does not stop the testsuite but obviously is an error.

I compared the schema definition, the Persister and the Parser and found some incompatibilities. I'll attach a spreadsheet with the outcome soon.
The red lines show the inconsitencies. The cells with underline those to be changed.
The only relevant change is, that the Parser will not see "next-date" as a required element.
Other changes only touch the schema document.
Along with this I renamed it from .xml to xsd.
Pull request will follow soon.