CODEWITHSUNDEEP
ruby-on-railspostgresql
timpone
timpone

Reputation: 19969

easiest way to convert a DateTime in rails for the non-timezone'd offset

I have a rails app that has the time zone set in application.rb with:

config.time_zone = 'Pacific Time (US & Canada)'

I'd like to save a time as:

day, hour=25, 10
....
params[:order][:pickup_at] = DateTime.new(2015,11,day,hour,00,00)

and thought it would write as 

2015-11-25 18:00:00

into our table which is a Postgres 9.4 instance and the pickup_at is a timestamp without time zone.

Instead it is: 

2015-11-25 10:00:00

doing: 

params[:order][:pickup_at] =DateTime.new(2015,11,25,10,00,00).in_time_zone("Pacific Time (US & Canada)")

doessn't fix. It seems what I'm trying to do is very simple. Into a timestamp adjust for what we have our current timezone set as and adjust accordingly.

How would I make this work?

Upvotes: 0

Views: 552

Answers (1)

voltair
voltair

Reputation: 621

DateTime has a default offset of 0, meaning it provides you a DateTime object in UTC ("non-timezone'd" as you put it) by default:

http://ruby-doc.org/stdlib-2.2.3/libdoc/date/rdoc/DateTime.html#method-c-new

If the UTC time you want to specify is 2015-11-25 18:00:00, you should write:

day, hour=25, 10
....
params[:order][:pickup_at] = DateTime.new(2015,11,day,hour,00,00,'-8')

That last -8 argument is the offset, which tells DateTime that your time zone is in PST.

DateTime.new(2015,11,day,hour,00,00,'-8').utc

then yields:

Wed, 25 Nov 2015 18:00:00 +0000

If you wanted to make this dynamic against your application's Time zone, you could write: 

day, hour = 25, 10
# Take application timezone offset in seconds and convert it to hours
hour_offset = Time.zone.utc_offset / 60 / 60 
params[:order][:pickup_at] = DateTime.new(2015,11,day,hour,00,00, hour_offset.to_s).utc

Upvotes: 0

Related Questions