diff --git a/src/app/_observation/select-date-time/select-date-time.component.html b/src/app/_observation/select-date-time/select-date-time.component.html
index 87a6b51..c4841d1 100644
--- a/src/app/_observation/select-date-time/select-date-time.component.html
+++ b/src/app/_observation/select-date-time/select-date-time.component.html
@@ -36,6 +36,8 @@
     <p>{{ dateForm.valid | json}}</p>
 </div> -->
 
+<!-- previous implementations from create / update observation components -->
+
 <!-- <div class="form-group adjust-size">
                         <label for="observationDateTime">Date & time</label>
                         <div class="date-time-control">
diff --git a/src/app/_observation/select-date-time/select-date-time.component.ts b/src/app/_observation/select-date-time/select-date-time.component.ts
index 78e4ab6..e779690 100644
--- a/src/app/_observation/select-date-time/select-date-time.component.ts
+++ b/src/app/_observation/select-date-time/select-date-time.component.ts
@@ -2,6 +2,9 @@ import { Component, Input, OnInit, ViewEncapsulation } from '@angular/core';
 import { NgbDate, NgbDateStruct, NgbTimeStruct } from '@ng-bootstrap/ng-bootstrap';
 import { FormGroup } from '@angular/forms';
 
+// ideally, it is better to write a proper validator
+// but added complexity because the ngb controls are binded to NgbDate & NgbTimeStruct models
+
 @Component({
   selector: 'app-select-date-time',
   templateUrl: './select-date-time.component.html',