  
  Database backends
  ~~~~~~~~~~~~~~~~~
  
  * ...
  
  Email
  ~~~~~
  
  * ...
 
</s> remove     @skipUnlessDBFeature("has_native_duration_field")
 </s> add     @skipUnlessDBFeature('supports_temporal_subtraction')
* Temporal data subtraction was unified on all backends.
  
  Database backends
  ~~~~~~~~~~~~~~~~~
  
* Temporal data subtraction was unified on all backends.
  
  Email
  ~~~~~
  
  * ...
keep keep keep keep replace keep keep keep keep keep
 Fixed #24793 -- Unified temporal difference support. 
docs/releases/1.10.txt