UNIX time format for Bustime SIRI response

[John S]

Does the Bustime API support returning timestamps etc in Unix time? I.e. per SIRI's documentation I've seen elsewhere, something like this should work but it doesn't seem to.

https://bustime.mta.info/api/siri/stop-monitoring.json?key=xxxx&OperatorRef=MTA&MonitoringRef=306421&LineRef=MTA%20NYCT_B67&LineRef=MTA%20NYCT_B69&&LineRef=MTA%20NYCT_B63&#TimeFormat=Unix