# Time zone and UTC offset

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 ?

On Nov 4, 5:32 pm, MR Damien [email protected] 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

Frederick C. wrote:

On Nov 4, 5:32ï¿½pm, MR Damien [email protected] 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

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

Frederick C. 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.