[ID] 7 [Location] 7.10.1 [Subject] Require UTC as default for time zone information [Followup] FS [Ed. / Subs.] S [Comment] 
The now function returns the current system date and time as a string value in the canonical XML Schema xsd:dateTime format. If time zone information is available, it is included (normalized to UTC). If no time zone information is available, an implementation default is used. Please require that the default is UTC. Otherwise the results of applying this function by different implementations might lead to dateTime values which are not totally ordered. See the Working with Time Zones for further guidance. Btw., in e.g. sec. 7.10.2 "The days-from-date() Function" you already require usage of UTC.