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.