In the last post I exposed some methods to calculate time difference in seconds, minutes and hours using Ruby on Rails. Today, we will explore how a small difference on time operations can become a nightmare when dealing with cache with expires_in parameter.

https://medium.com/little-programming-joys/be-aware-of-time-operations-when-using-cache-with-expires-in-ed8d8b5a93be#.tn210vigs