converting Date object to TimeWithZone

Question

I need to convert a Date object into a TimeWithZone object representing the beginning of that day in a given time zone.

The following approach works, but seems too convoluted as it requires me to convert the date to a string:

?> date = Date.parse("2010-02-17")
=> Wed, 17 Feb 2010
>> ActiveSupport::TimeZone['Eastern Time (US & Canada)'].parse(date.to_s)
=> Wed, 17 Feb 2010 00:00:00 EST -05:00
>> ActiveSupport::TimeZone['UTC'].parse(date.to_s)
=> Wed, 17 Feb 2010 00:00:00 UTC 00:00

Is there a better way I'm missing?

Edit: People are suggesting variations of:

?> date.to_datetime.in_time_zone('Eastern Time (US & Canada)').beginning_of_day
=> Tue, 16 Feb 2010 00:00:00 EST -05:00

As you can see, this isn't an equivalent conversion since it leaves me at the start of Feb. 16th EST, instead of the start of Feb. 17th EST.

Answer 1

You must first convert the date object to a DateTime object, and then apply the timezone you want.

date = Date.today
date.to_datetime.in_time_zone('UTC').beginning_of_day #Bad ideea, since the utc offset can also be negative, so you may end up with 'yesterday'.

In conclusion, a good ideea (and without involving parsing strings) would be:

date.to_datetime.in_time_zone('Eastern Time (US & Canada)') - ActiveSupport::TimeZone['Eastern Time (US & Canada)'].utc_offset
=> Wed, 17 Feb 2010 00:00:00 EST -05:00

Answer 2

Would something like this work for you?

'2010-04-01'.to_time.in_time_zone('Eastern Time (US & Canada)').beginning_of_day

Answer 3

-1 to everyone for confusing everything