Cumulative time in heart rate zones

I use a FR945 and I'm interested in viewing my cumulative time in different HR zones on a weekly / monthly basis after reading an article claiming a huge increase in VO2 max based on significant time in Zone 2.  Currently I can see the HR zones for each activity, but I'd have expected a simple way of seeing this data aggregated over different periods Garmin Connect has "Distance", "Time", "Ascent" and "Calories".  Surely a "Zones" tab would make complete sense?  Does anyone know if this is possible either on the watch, or else in Garmin land, or a 3rd party App that shows this in a meaningful way?  Many thanks!