Sure there is. But since it is not a continuous range there are the fixed separators --T::. between the parts. It is the javascript time format, which is a subs

Sure there is. But since it is not a continuous range there are the fixed separators --T::. between the parts. It is the javascript time format, which is a subset of the RFC3339 and ISO8601 time formats. The separators help at least to allow for a variable amount of sub-second digits.