I came across a rich ascii file (json-headed ascii) without units declared for the first column. Autoplot's ASCII parser parsed the ISO8601 strings, but the unit is not set in the bundleDescriptor, so numbers like 1e17 are shown for the X tags. When times have been detected and the rich ascii doesn't declare the units, go ahead and use the automatically detected units.
See https://jfaden.net/~jbf/autoplot/data/dat/richAscii/fromHapiToCDFTest.txt
This file was created by SpacePy.