diff --git a/.python-version b/.python-version
new file mode 100644
index 0000000..4f2c1d1
--- /dev/null
+++ b/.python-version
@@ -0,0 +1 @@
+3.6.6
diff --git a/app/devices/api.py b/app/devices/api.py
index 514de4b..cee336d 100644
--- a/app/devices/api.py
+++ b/app/devices/api.py
@@ -7,7 +7,7 @@ from .models import (Device,
                      DeviceType,
                      AccessLevel)
 from itsdangerous import URLSafeSerializer
-from app.core import app
+from app.core import app, db
 from app.jsonql import api as jsonql
 
 
@@ -335,7 +335,7 @@ def run_custom_query(device_id, request):
     if not Device.exists(id=device_id):
         raise ValueError("Device does not exist!")
 
-    def recording_field_provider(name):
+    def recording_field_provider(name, formatted=False):
         if name == 'record_value':
             return Recording.record_value
         if name == 'record_type':
@@ -343,8 +343,14 @@ def run_custom_query(device_id, request):
         if name == 'device_id':
             return Recording.device_id
         if name == 'recorded_at':
+            if formatted:
+                return db.func.to_char(
+                        Recording.recorded_at, 'YYYY-MM-DD"T"HH24:MI:SSOF')
             return Recording.recorded_at
         if name == 'received_at':
+            if formatted:
+                return db.func.to_char(
+                        Recording.received_at, 'YYYY-MM-DD"T"HH24:MI:SSOF')
             return Recording.received_at
 
     resulting_query = jsonql.run_query_on(Recording.query.with_entities(),
diff --git a/app/jsonql/api.py b/app/jsonql/api.py
index e051343..0219e41 100644
--- a/app/jsonql/api.py
+++ b/app/jsonql/api.py
@@ -7,11 +7,20 @@ ORDERS = ['asc', 'desc']
 
 
 def run_query_on(query_object, field_provider, **kwargs):
+    """
+    Generates a query for target object based on query provided as kwargs
+
+    :param query_object: Initial query object as returned by SQLAlchemy for
+    target table
+    :type query_object: Query
+    :param field_provider: Function which provides fields based on name, with
+    optional parameter formatted which returns the field formatted using sql
+    functions
+    :type field_provider: func(col_name:String, formatted:Boolean)
+    """
     selections, filters, groups, orderings = validate_selections(**kwargs)
     entities = []
 
-    print('Starting with args: ' + str(kwargs))
-
     if selections is not None:
         if groups is not None:
             for group in groups.keys():
@@ -26,9 +35,8 @@ def run_query_on(query_object, field_provider, **kwargs):
 
         for selection in selections.keys():
             entities.append(get_column(selections[selection],
-                            field_provider(selection)).label(selection))
+                            field_provider(selection, True)).label(selection))
 
-        print('New entities: ' + str(entities))
         query_object = query_object.with_entities(*entities)
 
     if filters is not None: