Sorry about the confusion.
I meant the DVR/Properties section in the file Application.xml, which is located in [install-dir]/conf/[ApplicationName]
We now recommend not using a time format with any dashes or colons, in fact, just use a numerical time format.
The Wowza nDVR Playlist Request API article has now been updated to reflect this:
if you look at the URL examples for UTC they now resemble this:
To do this you need to set the format with this property (again in the DVR/Properties section of your Application.xml file: