til/rails/get-the-current-time.md

Get The Current Time

Working with time and time zones in server development can get complicated. Time-sensitive code that worked locally can unexpected fail when deployed to a server in a different time zone. Or users can end up seeing timestamps that look a few hours off.

To avoid this kinds of mistakes in Rails development, we should avoid using Time.now and instead use Time.current.

Rails saves timestamps to the database in UTC time zone. We should always use Time.current for any database queries, so that Rails will translate and compare the correct times.

> Time.zone
=> #<ActiveSupport::TimeZone:0x00007fccf6b0a548
 @name="UTC",
 @tzinfo=#<TZInfo::DataTimezone: Etc/UTC>,
 @utc_offset=nil>
> Time.now
=> 2021-01-28 19:22:42.312577 -0600
> Time.current
=> Fri, 29 Jan 2021 01:22:45.926181000 UTC +00:00
> Time.zone = 'Eastern Time (US & Canada)'
=> "Eastern Time (US & Canada)"
> Time.now
=> 2021-01-28 19:23:28.255106 -0600
> Time.current
=> Thu, 28 Jan 2021 20:23:32.150545000 EST -05:00

My server's default time zone is UTC. Time.now gives me my computer's system time (Central Time). Time.current gives me the time in UTC. If I then change the server's time zone to Eastern Time, Time.now still offers up my system time whereas Time.current produces the current time in Easter Time.

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