Forum: Ruby on Rails Time zone and UTC offset

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9e8274f1e5340cc2efe0e4bc2f83121f?d=identicon&s=25 MR Damien (mrdamien)
on 2008-11-04 18:32
Hi all,

I am trying to change a date from a time zone to UTC.

First I set the time zone and then get its offset from UTC.

Then I am trying to change the time zone of my date by substracting the
offset  but it failed.

---------------
Time.zone = @time_zone # 'Paris'
@offset   = Time.zone.utc_offset() # @offset = 3600

# @date = now
@date = @date - @offset

# @date should be now - 1 but its somewhere in 1998 ...
---------------

Reading the pick axe Time documentation, when you substract something
from a date, it should be in seconds, which is the case. But with my
code, it failed.

What can I do to fix that ?
81b61875e41eaa58887543635d556fca?d=identicon&s=25 Frederick Cheung (Guest)
on 2008-11-04 19:02
(Received via mailing list)
On Nov 4, 5:32 pm, MR Damien <rails-mailing-l...@andreas-s.net> wrote:
> Time.zone = @time_zone # 'Paris'
> code, it failed.
>
Are you sure your date is an instance of Time and not an instance of
Date? (for Date - 1 means -1 day so -3600 would be about 10 years ie
somewhere in 1998).

Fred
9e8274f1e5340cc2efe0e4bc2f83121f?d=identicon&s=25 MR Damien (mrdamien)
on 2008-11-05 10:09
Frederick Cheung wrote:
> On Nov 4, 5:32�pm, MR Damien <rails-mailing-l...@andreas-s.net> wrote:
>> Time.zone = @time_zone # 'Paris'
>> code, it failed.
>>
> Are you sure your date is an instance of Time and not an instance of
> Date? (for Date - 1 means -1 day so -3600 would be about 10 years ie
> somewhere in 1998).
>
> Fred

Hi,

I am using DateTime.

@date = DateTime.strptime(params[:start_date], "%B %d, %Y %I:%M %p")

It seems that - 1 substract a day as you said. I will now search how to
convert a DateTime to Time.

Thanks
81b61875e41eaa58887543635d556fca?d=identicon&s=25 Frederick Cheung (Guest)
on 2008-11-05 15:22
(Received via mailing list)
On 5 Nov 2008, at 09:09, MR Damien wrote:

>>
> convert a DateTime to Time.
You can also use rails' date/time calculation things, for example

t += 5.seconds

does the right thing whether t is a Time or a DateTime

Fred
9e8274f1e5340cc2efe0e4bc2f83121f?d=identicon&s=25 MR Damien (mrdamien)
on 2008-11-06 15:32
Frederick Cheung wrote:
> On 5 Nov 2008, at 09:09, MR Damien wrote:
>
>>>
>> convert a DateTime to Time.
> You can also use rails' date/time calculation things, for example
>
> t += 5.seconds
>
> does the right thing whether t is a Time or a DateTime
>
> Fred

Hey,

Thanks for that trick.
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