We improved REST API for ClaimDefinition to support activation time. Please note that while the api schema supports an array of activation times, only the first one is used by Identify at the moment. Example:

“activationTimes”: [
   {
     “EndTime”: “2016-08-01T09:23:43.506Z”,
     “StartTime”: “2017-08-01T09:23:43.506Z”
   }
],

You can refer to https://github.com/Safewhere/Safewhere-Identify-samples to see the sample code.