Histogram2 with datetime variables

I'm trying to graph some data in a 2d histogram I need this data to be versus time in half hour increments. I have my initial time data in decimal day units, and have converted it to datetime and seconds from epoch using posixtime. My problem is I want the Xtick labels to be in a datetime format like hh:mm, but histogram2 doesn't work with datetime variables, so I can't use that. And anytime I graph with the seconds I find it impossible to convert the tick labels to a readable datetime format. How would I do this?

I'm going over two days (134.0 - 135.99) with bins every half hour. If you need any more information pleas elet me know, I'm trying to do this today. Below is some of my time data:

Decimal Days:                
134.001667000000
134.004444000000
134.007222000000
134.010000000000
134.012778000000
134.015556000000
134.018333000000
134.146111000000
134.148889000000
134.151667000000
134.154444000000
134.157222000000
134.160000000000
134.162778000000
134.165556000000
134.168333000000
134.171111000000
134.173889000000
134.176667000000
134.179444000000
134.182222000000
134.185000000000

[dpb]

" datetime format like hh:mm"

From when? What do you want 134.001667 days to be? A duration in hh:mm?

[Cordelia David]

The date of 134 decimal days is May 15th, 2014. I want to graph my data against the array of time I have, whether that's datetime, seconds, duration or whatever. The main thing is that the x tick labels are in a time format so the graph is readable.

[dpb]

See doc Examples for datetick -- they show a bar3 example -- I think you can do same thing with histogram if use the deprecated datenum

Does seem worthy enhancement request for all the bar and histogram routines -- dunno why they've been left out.

There is a problem that datetick doesn't know about durations so can't label with hours > 0-23--the only way around that I can see would be to create a second time axes from same position as the histogram2 and put the annotations on it.