Option to allow 'Today' button to set date-time in UTC (or other time zone)

When clicking on the 'Today' button, the default date-time is set according to the (client) local timezone. However, for a project I'm working on I require input in UTC. Having the ability to set the timezone for the picker would be very useful, though for my purposes a simple flag to indicate that UTC should be used, rather than local time, would suffice.