All objects have created and updated date properties. Dates are encoded as strings following the ISO 8601 standard. (2017-06-01T17:18:11.345Z)

On all List endpoints, objects can be filtered by date using the from and to parameters.

curl -X GET \
  'https://api.fidel.uk/v1/programs/e1d96ed3-dfd6-4896-8e57-37dca8b1c394/transactions?from=2019-10-26T00:00:00.000Z&to=2019-10-27T23:59:59.000Z' \
  -H 'content-type: application/json' \
  -H 'fidel-key: sk_test_50ea90b6-2a3b-4a56-814d-1bc592ba4d63'

On the List Transactions endpoint the date filtering is applied on the datetime property considering no timezone information. You can access On the other List endpoints the filtering is applied on the created property.