Question

We have a very simple payments model with the default “created_at” datetime field that we have to search in a date range so I did this:

>> Payment.all(:conditions => 
              ["Date(payments.created_at) >= ? and 
                Date(payments.created_at) <= ?", start_date, end_date])

I’m having an issue with the Date function. For example

>> Payment.find(2577).created_at
=> Thu, 15 Dec 2011 18:15:00 UTC +00:00

But

>> Payment.find(2577).created_at.localtime
=> Fri Dec 16 01:15:00 +0700 2011

So when we search for payments on Dec 16 we don’t get any results since Date(payments.created_at) converts the UTC time to date which gets converted to Dec 15.

Is it possible to modify Date(payments.created_at) so that it searches for dates the local timezone instead? We are using Rails 2.3.5 and postgresql.

Answer 1

Finally got it to work! Not very pretty (and I’m hoping there’s a cleaner solution) but this worked:

>> Payment.all(:conditions => 
              ["Date((payments.created_at at time zone 'UTC') 
                at time zone :timezone) >= :start_date and 
                Date((payments.created_at at time zone 'UTC') 
                at time zone :timezone) <= :end_date",
               :start_date => start_date, :end_date => end_date, 
               :timezone => 'Asia/Katmandu'])

Not really liking having to do this though:

Date((payments.created_at at time zone 'UTC') at time zone 'Asia/Katmandu')

How come postgresql doesn’t let you just do this?

Date(payments.created_at at 'Asia/Katmandu')