I've been trying to export a mailbox between two dates. From the REST documentation in /opt/zimbra/docs/rest.txt (no online documentation available since version 6 apparently, and I'm running 8.0 ....), I have been trying various things.

I can get relative dates to work OK.
zmmailbox -z -m account@domain.com getRestURL "//?fmt=tgz&start=-1mon&end=0day" > /tmp/archive-lastmonth.tgz
The absolute dates should apparently be in the format
mm/dd/yyyy (i.e., 12/25/1998)
yyyy/dd/mm (i.e., 1989/12/25)
... (dear god why?), but anyway even when against my better judgement I switch days and months around, the export fails with a message about not being able to access the URL. Has someone got this to work. eg
zmmailbox -z -m account@domain.com getRestURL "//?fmt=tgz&start=20130102&end=20130319" > /tmp/archive-daterange.tgz
I notice that the Preferences > Export page uses num milliseconds format. I suppose I could use that, but really I'd prefer something I can do without having to resort to a calculator every time.

Also, bonus question. I assume I can also use the date ranges when I'm importing with postRestURL?

And in case this helps someone out ... I initially had a full export fail as it got stuck at 5.1Gb. Didn't figure out what was happening until I logged into the admin webmail and saw a zillion messages telling me the disk had filled up. So, moral of the story is don't blindly follow examples which tell you to export into /tmp/output.tgz!