Platform update may have effected dates?

Platform update may have effected dates?

An application that was working perfectly for months stopped working today around 9:30 am NY time. At this same time, the app started to experience a very long duration upon submit actions. 

After spending hours diagnosing things (the logs did not show any errors), I decided to remove this bit of code (submit action)

  1. if((input.DELIVERY   ==  zoho.currentdate)  &&  (input.REMINDER  ==  null))
  2. {
  3. // some code that sends an email
  4. }

to

  1. //some code that sends an email
and observed two things: 1) The code now works 2) The very long delay we started seeing was gone.

Both variables above are date-only fields. 

Any ideas?

Cheers,
John Whitney