In one Form the user also has to specify a date for example the 21.04.2014:
So when a post request is sent to the rails-application, to save a post there is also provided a created_at data in the request:
post[text]:"First Message"
post[created_at]:21.04.2014
So at the end a message is saved. Now when i try to get the created_at for the message:
Message.find(1).created_at
>> 2014-04-21 00:00:00
But i would like that the time corresponds to the actual time when the message was created, so the ouput must look something like this:
>> 2014-04-21 19:52:07
How do i have to save the message so that it meets my concept? Thanks
Actual i save a message like this:
#user.message.new(message_params)
def diagnosis_params
params[:message].permit(:created_at, :text)
end
You can do something like this:
dt = Date.parse('21.04.2014')
# => Mon, 21 Apr 2014
tm = Time.zone.now
# => Tue, 22 Apr 2014 00:34:07 MSK +04:00
created_at = DateTime.new(dt.year, dt.month, dt.day, tm.hour, tm.min, tm.sec)
# => Mon, 21 Apr 2014 00:34:07 +0000
Not very elegant but you can create some utility method...
Related
I have a record foo in the database which has :start_time and :timezone attributes.
The :start_time is a Time in UTC - 2001-01-01 14:20:00, for example.
The :timezone is a string - America/New_York, for example.
I want to create a new Time object with the value of :start_time but whose timezone is specified by :timezone. I do not want to load the :start_time and then convert to :timezone, because Rails will be clever and update the time from UTC to be consistent with that timezone.
Currently,
t = foo.start_time
=> 2000-01-01 14:20:00 UTC
t.zone
=> "UTC"
t.in_time_zone("America/New_York")
=> Sat, 01 Jan 2000 09:20:00 EST -05:00
Instead, I want to see
=> Sat, 01 Jan 2000 14:20:00 EST -05:00
ie. I want to do:
t
=> 2000-01-01 14:20:00 UTC
t.zone = "America/New_York"
=> "America/New_York"
t
=> 2000-01-01 14:20:00 EST
Sounds like you want something along the lines of
ActiveSupport::TimeZone.new('America/New_York').local_to_utc(t)
This says convert this local time (using the zone) to utc. If you have Time.zone set then you can of course to
Time.zone.local_to_utc(t)
This won't use the timezone attached to t - it assumes that it's local to the time zone you are converting from.
One edge case to guard against here is DST transitions: the local time you specify may not exist or may be ambiguous.
I've just faced the same problem and here is what I'm going to do:
t = t.asctime.in_time_zone("America/New_York")
Here is the documentation on asctime
If you're using Rails, here is another method along the lines of Eric Walsh's answer:
def set_in_timezone(time, zone)
Time.use_zone(zone) { time.to_datetime.change(offset: Time.zone.now.strftime("%z")) }
end
You need to add the time offset to your time after you convert it.
The easiest way to do this is:
t = Foo.start_time.in_time_zone("America/New_York")
t -= t.utc_offset
I am not sure why you would want to do this, though it is probably best to actually work with times the way they are built. I guess some background on why you need to shift time and timezones would be helpful.
Actually, I think you need to subtract the offset after you convert it, as in:
1.9.3p194 :042 > utc_time = Time.now.utc
=> 2013-05-29 16:37:36 UTC
1.9.3p194 :043 > local_time = utc_time.in_time_zone('America/New_York')
=> Wed, 29 May 2013 12:37:36 EDT -04:00
1.9.3p194 :044 > desired_time = local_time-local_time.utc_offset
=> Wed, 29 May 2013 16:37:36 EDT -04:00
Depends on where you are going to use this Time.
When your time is an attribute
If time is used as an attribute, you can use the same date_time_attribute gem:
class Task
include DateTimeAttribute
date_time_attribute :due_at
end
task = Task.new
task.due_at_time_zone = 'Moscow'
task.due_at # => Mon, 03 Feb 2013 22:00:00 MSK +04:00
task.due_at_time_zone = 'London'
task.due_at # => Mon, 03 Feb 2013 22:00:00 GMT +00:00
When you set a separate variable
Use the same date_time_attribute gem:
my_date_time = DateTimeAttribute::Container.new(Time.zone.now)
my_date_time.date_time # => 2001-02-03 22:00:00 KRAT +0700
my_date_time.time_zone = 'Moscow'
my_date_time.date_time # => 2001-02-03 22:00:00 MSK +0400
Here's another version that worked better for me than the current answers:
now = Time.now
# => 2020-04-15 12:07:10 +0200
now.strftime("%F %T.%N").in_time_zone("Europe/London")
# => Wed, 15 Apr 2020 12:07:10 BST +01:00
It carries over nanoseconds using "%N". If you desire another precision, see this strftime reference.
The question's about Rails but it seems, like me, not everyone here is on the ActiveSupport train, so yet another option:
irb(main):001:0> require "time"
=> true
irb(main):003:0> require "tzinfo"
=> true
irb(main):004:0> t = Time.parse("2000-01-01 14:20:00 UTC")
=> 2000-01-01 14:20:00 UTC
irb(main):005:0> tz = TZInfo::Timezone.get("America/New_York")
=> #<TZInfo::DataTimezone: America/New_York>
irb(main):008:0> utc = tz.local_to_utc(t)
=> 2000-01-01 19:20:00 UTC
irb(main):009:0> tz.utc_to_local(utc)
=> 2000-01-01 14:20:00 -0500
irb(main):010:0>
local_to_utc not doing the opposite of utc_to_local might look like a bug but it is at least documented: https://github.com/tzinfo/tzinfo says:
The offset of the time is ignored - it is treated as if it were a local time for the time zone
I managed to do this by calling change with the desired time zone:
>> t = Time.current.in_time_zone('America/New_York')
=> Mon, 08 Aug 2022 12:04:36.934007000 EDT -04:00
>> t.change(zone: 'Etc/UTC')
=> Mon, 08 Aug 2022 12:04:36.934007000 UTC +00:00
https://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html#method-i-change
def relative_time_in_time_zone(time, zone)
DateTime.parse(time.strftime("%d %b %Y %H:%M:%S #{time.in_time_zone(zone).formatted_offset}"))
end
Quick little function I came up with to solve the job. If someone has a more efficient way of doing this please post it!
I spent significant time struggling with TimeZones as well, and after tinkering with Ruby 1.9.3 realized that you don't need to convert to a named timezone symbol before converting:
my_time = Time.now
west_coast_time = my_time.in_time_zone(-8) # Pacific Standard Time
east_coast_time = my_time.in_time_zone(-5) # Eastern Standard Time
What this implies is that you can focus on getting the appropriate time setup first in the region you want, the way you would think about it (at least in my head I partition it this way), and then convert at the end to the zone you want to verify your business logic with.
This also works for Ruby 2.3.1.
I have created few helper methods one of which just does the same thing as is asked by the original author of the post at Ruby / Rails - Change the timezone of a Time, without changing the value.
Also I have documented few peculiarities I observed and also these helpers contains methods to completely ignore automatic day-light savings applicable while time-conversions which is not available out-of-the-box in Rails framework:
def utc_offset_of_given_time(time, ignore_dst: false)
# Correcting the utc_offset below
utc_offset = time.utc_offset
if !!ignore_dst && time.dst?
utc_offset_ignoring_dst = utc_offset - 3600 # 3600 seconds = 1 hour
utc_offset = utc_offset_ignoring_dst
end
utc_offset
end
def utc_offset_of_given_time_ignoring_dst(time)
utc_offset_of_given_time(time, ignore_dst: true)
end
def change_offset_in_given_time_to_given_utc_offset(time, utc_offset)
formatted_utc_offset = ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, false)
# change method accepts :offset option only on DateTime instances.
# and also offset option works only when given formatted utc_offset
# like -0500. If giving it number of seconds like -18000 it is not
# taken into account. This is not mentioned clearly in the documentation
# , though.
# Hence the conversion to DateTime instance first using to_datetime.
datetime_with_changed_offset = time.to_datetime.change(offset: formatted_utc_offset)
Time.parse(datetime_with_changed_offset.to_s)
end
def ignore_dst_in_given_time(time)
return time unless time.dst?
utc_offset = time.utc_offset
if utc_offset < 0
dst_ignored_time = time - 1.hour
elsif utc_offset > 0
dst_ignored_time = time + 1.hour
end
utc_offset_ignoring_dst = utc_offset_of_given_time_ignoring_dst(time)
dst_ignored_time_with_corrected_offset =
change_offset_in_given_time_to_given_utc_offset(dst_ignored_time, utc_offset_ignoring_dst)
# A special case for time in timezones observing DST and which are
# ahead of UTC. For e.g. Tehran city whose timezone is Iran Standard Time
# and which observes DST and which is UTC +03:30. But when DST is active
# it becomes UTC +04:30. Thus when a IRDT (Iran Daylight Saving Time)
# is given to this method say '05-04-2016 4:00pm' then this will convert
# it to '05-04-2016 5:00pm' and update its offset to +0330 which is incorrect.
# The updated UTC offset is correct but the hour should retain as 4.
if utc_offset > 0
dst_ignored_time_with_corrected_offset -= 1.hour
end
dst_ignored_time_with_corrected_offset
end
Examples which can be tried on rails console or a ruby script after wrapping the above methods in a class or module:
dd1 = '05-04-2016 4:00pm'
dd2 = '07-11-2016 4:00pm'
utc_zone = ActiveSupport::TimeZone['UTC']
est_zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
tehran_zone = ActiveSupport::TimeZone['Tehran']
utc_dd1 = utc_zone.parse(dd1)
est_dd1 = est_zone.parse(dd1)
tehran_dd1 = tehran_zone.parse(dd1)
utc_dd1.dst?
est_dd1.dst?
tehran_dd1.dst?
ignore_dst = true
utc_to_est_time = utc_dd1.in_time_zone(est_zone.name)
if utc_to_est_time.dst? && !!ignore_dst
utc_to_est_time = ignore_dst_in_given_time(utc_to_est_time)
end
puts utc_to_est_time
Hope this helps.
This worked well for me
date = '23/11/2020'
time = '08:00'
h, m = time.split(':')
timezone = 'Europe/London'
date.to_datetime.in_time_zone(timezone).change(hour: h, min: m)
This changes the timezone to 'EST' without changing the time:
time = DateTime.current
Time.find_zone("EST").local(
time.year,
time.month,
time.day,
time.hour,
time.min,
time.sec,
)
There are two issues here:
I have this code to publish on users' facebook walls:
def publish_on_facebook
if user.last_published < 1.day.ago
#graph = Koala::Facebook::API.new(user.service.token)
begin
#graph.put_wall_post("some post")
user.last_published = Time.now
user.save
rescue
user.last_published = 1.week.from_now
user.save
end
end
end
It works perfectly:
if the user has authorized me, it publishes and updates the last_published (type datetime) field to now.
If the user has not authorized me to publish stuff in his wall, then it updates the last_published field to 1 week from now.
Now when I run in through my Cucumber, testing, it doesn't work:
When the user has authorized me, the last_published field updates to 1 minute from now, but 2 days ago
expected: > Sun, 03 Mar 2013 16:12:44 UTC +00:00
got: Fri, 01 Mar 2013 16:13:43 UTC +00:00
When the user hasn't authorized me, no change on the last_published field (i set the default value of the field to march 1st)
expected: > Sat, 09 Mar 2013 16:13:47 UTC +00:00
got: Fri, 01 Mar 2013 15:01:11 UTC +00:00
Any ideas?
When updating attributes, the variable #user must be reloaded:
#user.update_attributes(attribute: value)
#user = User.find(#user)
Cucumber was evaluating the values stored in #user, which were not up to date after the method ran.
Time.parse returns a Time object that does not have a timezone. I would like to keep the timezone information. Is there a better way to do this then the following code?
def parse_with_timezone( string_input)
/(.*)([+-]\d\d):?(\d\d)$/.match( string_input) do |match|
tz = ActiveSupport::TimeZone[match[2].to_i.hours + match[3].to_i.minutes]
tz.parse( match[1])
end
end
The input is a string like this "2012-12-25T00:00:00+09:00". This function outputs a TimeWithZone object.
Were you looking for a specific timezone of the current local one?
# Current zone
1.9.3p194> Time.zone.parse('2012-12-25T00:00:00+09:00')
=> Mon, 24 Dec 2012 15:00:00 UTC +00:00
Console was set at UTC for above but will work for whatever you have configured
# Specific timezone
1.9.3p194> Time.find_zone('Wellington').parse('2012-12-25T00:00:00+09:00')
=> Tue, 25 Dec 2012 04:00:00 NZDT +13:00
I notice you're trying to pass +9 so as an example
1.9.3p194> Time.zone = 'Tokyo'
=> "Tokyo"
1.9.3p194> Time.zone.parse('2012-12-25T00:00:00+09:00')
=> Tue, 25 Dec 2012 00:00:00 JST +09:00
Gives you the right result.
What about the Rails Timezone API: http://api.rubyonrails.org/classes/ActiveSupport/TimeZone.html
I prefer to use Chronic for all my date/time parsing needs.
I have a DateTime object representing a particular date, as in "2011-01-15 00:00:00 UTC" to represent January 15th. I would like to produce the range of times in a particular time zone that have the same date.
The method signature would probably be something like
def day_range_for(date, tz)
# ...
end
For example, if I have range_for(DateTime.parse('2011-01-15'), 'CST'), then I want the result to be a range like 2011-01-15 00:00:00 -0600 .. 2011-01-15 23:59:59 -0600.
Can you take the input string instead of the object? If you pass in a DateTime object, its a tad counter intuitive because the time the object represents isn't the actual time you are looking for. It would conform to my expectations if you either passed in the correct, absolute DateTime, or the string itself. The actual meat of the problem is entirely handled by ActiveSupport, which I think you are using since you tagged this question with Rails. How does this look?
def range_for(input, tz=nil)
if tz.is_a?(String)
tz = ActiveSupport::TimeZone.new(tz)
else
tz = Time.zone
end
if input.acts_like?(:date) || input.acts_like?(:time)
d = input.in_time_zone(tz)
else
d = tz.parse(input)
end
return d.beginning_of_day..d.end_of_day
end
Have a look:
ruby-1.9.2-p0 > range_for('2011-01-15', 'Alaska')
=> Sat, 15 Jan 2011 00:00:00 AKST -09:00..Sat, 15 Jan 2011 23:59:59 AKST -09:00
ruby-1.9.2-p0 > range_for(Time.zone.now)
=> Mon, 10 Jan 2011 00:00:00 EST -05:00..Mon, 10 Jan 2011 23:59:59 EST -05:00
ruby-1.9.2-p0 > range_for('2011-01-15', 'EST')
=> Sat, 15 Jan 2011 00:00:00 EST -05:00..Sat, 15 Jan 2011 23:59:59 EST -05:00
How about:
def day_range_for date, zone
(DateTime.new(date.year,date.month,date.day,0,0,0,zone)..DateTime.new(date.year,date.month,date.day,23,59,59,zone))
end
day_range_for(DateTime.parse('2011-01-15'), 'CST')
#=> #<DateTime: 2011-01-15T00:00:00-06:00 (9822307/4,-1/4,2299161)>..#<DateTime: 2011-01-15T23:59:59-06:00 (212161917599/86400,-1/4,2299161)>
I am trying to create a page to display a list of links for each month, grouped into years. The months need to be between two dates, Today, and The date of the first entry.
I am at a brick wall, I have no idea how to create this.
Any help would be massively appriciated
Regards
Adam
Just put what you want inside a range loop and use the Date::MONTHNAMES array like so
(date.year..laterdate.year).each do |y|
mo_start = (date.year == y) ? date.month : 1
mo_end = (laterdate.year == y) ? laterdate.month : 12
(mo_start..mo_end).each do |m|
puts Date::MONTHNAMES[m]
end
end
The following code will add a months_between instance method to the Date class
#!/usr/bin/ruby
require 'date'
class Date
def self.months_between(d1, d2)
months = []
start_date = Date.civil(d1.year, d1.month, 1)
end_date = Date.civil(d2.year, d2.month, 1)
raise ArgumentError unless d1 <= d2
while (start_date < end_date)
months << start_date
start_date = start_date >>1
end
months << end_date
end
end
This is VERY lightly tested, however it returns an Array of dates each date being the 1st day in each affected month.
I don't know if I've completely understood your problem, but some of the following might be useful. I've taken advantage of the extensions to Date provided in ActiveSupport:
d1 = Date.parse("20070617") # => Sun, 17 Jun 2007
d2 = Date.parse("20090529") #=> Fri, 29 May 2009
eom = d1.end_of_month #=> Sat, 30 Jun 2007
mth_ends = [eom] #=> [Sat, 30 Jun 2007]
while eom < d2
eom = eom.advance(:days => 1).end_of_month
mth_ends << eom
end
yrs = mth_ends.group_by{|me| me.year}
The final line uses another handy extension: Array#group_by, which does pretty much exactly what it promises.
d1.year.upto(d2.year) do |yr|
puts "#{yrs[yr].min}, #{yrs[yr].max}"
end
2007-06-30, 2007-12-31
2008-01-31, 2008-12-31
2009-01-31, 2009-05-31
I don't know if the start/end points are as desired, but you should be able to figure out what else you might need.
HTH
Use the date_helper gem which adds the months_between method to the Date class similar to Steve's answer.
xmas = Date.parse("2013-12-25")
hksar_establishment_day = Date.parse("2014-07-01")
Date.months_between(xmas,hksar_establishment_day)
=> [Sun, 01 Dec 2013, Wed, 01 Jan 2014, Sat, 01 Feb 2014, Sat, 01 Mar 2014, Tue, 01 Apr 2014, Thu, 01 May 2014, Sun, 01 Jun 2014, Tue, 01 Jul 2014]