Tweak datetime picker layout for mobile

public/sass/components/_timepicker.scss

@@ -20,9 +20,12 @@
   display: flex;
   flex-direction: column;
   position: absolute;
+  left: 20px;
   right: 20px;
   top: $navbarHeight;
-  width: 550px;
+  @include media-breakpoint-up(md) {
+    width: 550px;
+  }
 
   .popover-box {
     max-width: 100%;