diff --git a/README.md b/README.md
index a6b4f76..bea820b 100644
--- a/README.md
+++ b/README.md
@@ -21,4 +21,4 @@ or
 
 `$ http --session=./session.json GET "http://127.0.0.1:5000/api/attendance/student?identifier=3&start_time=now&end_time=now"`
 #### Class:
-`$ http --session=./session.json GET "http://127.0.0.1:5000/api/attendance/class?identifier=1&start_time=now&end_time=now"`
+`$ http --session=./session.json GET "http://127.0.0.1:5000/api/attendance/class?identifier=1"`
diff --git a/server.py b/server.py
index 83c3436..ee91113 100644
--- a/server.py
+++ b/server.py
@@ -74,20 +74,22 @@ def parse_time(time_str):
     utc_now = (time_str and time_str == 'now') or not time_str
     time = datetime.utcnow() if utc_now else None
     try:
-        time = parser.parse(attend_date)
+        time = parser.parse(time_str)
     except:
         pass
     return time
 
 
 def compute_attendance(request_type, object_id, start_time, end_time):
+    print('AttendanceUpdates for :', start_time, end_time)
+
     def get_records(req_type, obj_id):
         return AttendanceUpdate.query.filter(
             AttendanceUpdate.update_type == req_type).filter(
                 AttendanceUpdate.value_identifier == obj_id).filter(
                     func.date(AttendanceUpdate.time) >=
                     start_time.date()).filter(
-                        func.date(AttendanceUpdate.time) >=
+                        func.date(AttendanceUpdate.time) <=
                         end_time.date()).all()
 
     def student_records(stud_id):
@@ -97,10 +99,12 @@ def compute_attendance(request_type, object_id, start_time, end_time):
         pres_rec = stud_recs
         for gr in gcls_recs:
             # if any grade record overlaps with student record -> ignore
-            if not any(map(lambda x:gr.time.date()==x.time.date(),stud_recs)):
+            if not any(
+                    map(lambda x: gr.time.date() == x.time.date(), stud_recs)):
                 pres_rec.append(gr)
         recs = []
-        for r in pres_rec:
+        # sort student records by time
+        for r in sorted(pres_rec, key=lambda x: x.time):
             recs.append({
                 "presence": presense_map[r.presence].lower(),
                 "student": stud.student_name,
@@ -113,6 +117,7 @@ def compute_attendance(request_type, object_id, start_time, end_time):
         result.extend(student_records(object_id))
     if request_type == 'class':
         gcls = Gradeclass.query.get(object_id)
+        # get result for each student
         for stud in gcls.students:
             result.extend(student_records(stud.id))
     return result