What is the best way to represent a time field in a swagger specification, the closest type to denote it looks like date-time
but this makes standard deserialis
Depending on what you're trying to represent, this may or may not be a good idea.
If you want to represent a specific timestamp, then it's probably much safer to include the date.
If the date really isn't important (eg. you want to indicate that an event takes place at 14:00 every day), then I don't believe swagger has a built in format for that. However, the swagger format field is open and swagger has support for ECMA 262 regex string patterns.