I'm trying to convert the time which is in IST to EST using Ruby(NOT Rails). I tried different ways. But its returning the time in UTC. here is the example.
08/08/2014 01:45 AM
Is there any way to convert the above date into EST.
Try this
require 'time'
ist = Time.parse('08/08/2014 01:45 AM +05:30')
p ist
est = ist.getlocal("-05:00")
p est
Output
2014-08-08 01:45:00 +0530
2014-08-07 15:15:00 -0500
[Finished in 0.1s]
First I would check out a couple methods in the Time class in ruby's documentation http://ruby-doc.org/core-2.2.1/Time.html#method-i-2B
Specifically Time#now Time#strftime Time#-
To start off I am going to assume that you are in Indian Standard Time and would like to know what time it is for your friend in Eastern Standard Time. According to google.com.. IST is 9 and 1/2 hours ahead of EST. Which means you need to get your current time in IST and subtract 9.5 hours. See if this is what your looking for..
#Simple Method That Takes a Time Argument
#If you read correctly, Time#- uses seconds.
def to_est(ist)
(ist - 34200).strftime("%m/%d/%Y %I:%M%p")
end
#Calling the method
puts to_est(Time.now)
%m = Month
%d = Day
%Y = Year
%I = Hour
%M = Minute
%p = Meridian Indicator
Related
How do I convert UTC timestamp in the format '2009-02-02 00:00:00' to EST/EDT in Ruby? Note that I am not using Rails, instead it is a simple Ruby script.
1If the date range falls between EST (usually Jan-Mid March) it needs to to UTC-5hrs. For EDT it is UTC-4hrs.
So far I have the following function to convert UTC to EST/EDT.
def utc_to_eastern(utc)
eastern = Time.parse(utc) # 2009-02-02 00:00:00 -0500
offset_num = eastern.to_s.split(" -")[1][1].to_i # 5
eastern_without_offset = (eastern-offset_num*60*60).strftime("%F %T") # 2009-02-01 19:00:00
return eastern_without_offset
end
puts utc_to_eastern("2009-02-02 00:00:00") # 2009-02-01 19:00:00
puts utc_to_eastern("2009-04-02 00:00:00") # 2009-04-01 20:00:00
The above code does what I want, however there's two issues with my solution:
I do not want to reinvent the wheel, meaning I do not wish to write the time conversion functionality instead use existing methods provided by Ruby. Is there a more intuitive way to do this?
The parsing uses my local timezone to convert UTC to EST/EDT, however I would like to explicitly define the timezone conversion ("America/New_York"). Because this means someone running this on a machine on central time would not be using EST/EDT.
The best approach would be to use TZInfo.
require 'tzinfo'
require 'time'
def utc_to_eastern utc
tz = TZInfo::Timezone.get("America/New_York")
tz.to_local(Time.parse(utc)).strftime('%Y-%m-%d %H:%M:%S')
end
utc_to_eastern "2020-02-02 00:00:00 UTC" => "2020-02-01 19:00:00"
utc_to_eastern "2020-04-02 00:00:00 UTC" => "2020-04-01 20:00:00"
I am capturing the current time like so:
Time.now
My server runs on UTC. How can I convert the time to EST without using any Rails libraries? I am guessing some sort of offset but not sure how it works per say.
In plain Ruby you may use Time.zone_offset method:
require 'time'
t = Time.now # 2014-07-30 18:30:00 UTC
t + Time.zone_offset('EST') # 2014-07-30 13:30:00 UTC
The fbonetti's answer leads to the proper UTC to Eastern time conversion while accepted David Unric's answer would give wrong time for 8 months in 2017 (while DST is in effect).
Let's look at the following example:
First we'll need to figure out when DST starts/ends in 2017:
As we can see on March 12th, 2017 deep in the night (2:00am) they change time by adding +1 hour, so they "jump" from 1:59:59am up to 3:00:00am instantaneously! Which means there can not be 2:30am on March 12th, 2017.
Let's choose two UTC timestamps - one before and one after that switch, then we will try to convert those two timestamps from UTC back to Eastern.
First timestamp will be safely far enough from the switch moment:
require 'time'
t1 = Time.parse("2017-03-11 15:00:00 +0000")
=> 2017-03-11 15:00:00 +0000
t1_epoch_s = t1.to_i
=> 1489244400
Second timestamp is just +24 hours from the first one:
t2 = Time.parse("2017-03-12 15:00:00 +0000")
=> 2017-03-12 15:00:00 +0000
t2_epoch_s = t2.to_i
=> 1489330800
Now let us convert t1_epoch_s and t2_epoch_s to Eastern:
method-1: by adding Time.zone_offset('EST')
wrong, gives bad result: 10am for both days :(
and offset portion is shown as "+0000" which is also misleading and would refer to completely wrong point in time for people reading our output : ((
Time.at(t1_epoch_s) + Time.zone_offset('EST')
=> 2017-03-11 10:00:00 +0000
Time.at(t2_epoch_s) + Time.zone_offset('EST')
=> 2017-03-12 10:00:00 +0000
method-2: by changing timezone
Good!! Correctly yields 10am and 11am on next day!-)
ENV['TZ'] = 'America/New_York'
Time.at(t1_epoch_s)
=> 2017-03-11 10:00:00 -0500
Time.at(t2_epoch_s)
=> 2017-03-12 11:00:00 -0400
# resetting timezone back
ENV['TZ'] = nil
Basically manually adding Time.zone_offset('EST') is like adding constant and it will give right result for about 4 months (of 12 total) during the year, but then other time you'd have to manually add Time.zone_offset('EDT'), which is another constant. It pretty much same as "a broken clock is right twice a day": )) nasty!
And just for laughter let's see the "slow mo" how proper method handles the actual +1 hour magic jump in time:
ENV['TZ'] = "America/New_York"
Time.at(1489301999 + 0)
=> 2017-03-12 01:59:59 -0500
Time.at(1489301999 + 1)
=> 2017-03-12 03:00:00 -0400
ENV['TZ'] = nil
magic-magic!
In plain ruby, the timezone is determined by the 'TZ' environment variable. You could do something like this:
ENV['TZ'] = 'America/New_York' # set the TZ to Eastern Daylight Time
time = Time.now
time.zone
# => "EDT"
# do stuff
ENV['TZ'] = nil # reset the TZ back to UTC
If you don't mind using a gem,
require 'tzinfo'
tz = TZInfo::Timezone.get('US/Eastern')
Time.now.getlocal(tz.current_period.offset.utc_total_offset)
Credit: https://stackoverflow.com/a/42702906/2441263
I am trying to parse a datetime with Time class in Ruby 2.0. I can't figure out how to parse date and get it in a specified timezone. I have used Time.zone.parse to parse a date where I first call Time.zone and set it to a specified timezone. In the below example, I set the zone but it does not effect strptime, I have tried doing Time.zone.parse(date) but I can't get it parse a date like the one below.
Time.zone = "Central Time (US & Canada)"
#=> "Central Time (US & Canada)"
irb(main):086:0> Time.strptime("08/26/2013 03:30 PM","%m/%d/%Y %I:%M %p")
#=> 2013-08-26 15:30:00 -0400
Time.zone isn’t a part of Ruby, it’s a part of ActiveSupport (which is included with Rails). As such, strptime does not know about Time.zone at all. You can, however, convert a normal Ruby Time into an ActiveSupport::TimeWithZone using in_time_zone, which uses Time.zone’s value by default:
require 'active_support/core_ext/time'
Time.zone = 'Central Time (US & Canada)'
time = Time.strptime('08/26/2013 03:30 PM', '%m/%d/%Y %I:%M %p')
#=> 2013-08-26 15:30:00 -0400
time.in_time_zone
#=> Mon, 26 Aug 2013 14:30:00 CDT -05:00
If you are only looking at Ruby2.0, you may find the time lib useful:
require 'time'
time.zone # return your current time zone
a = Time.strptime("08/26/2013 03:30 PM","%m/%d/%Y %I:%M %p")
# => 2013-08-26 15:30:00 +1000
a.utc # Convert to UTC
a.local # Convert back to local
# Or you can add/subtract the offset for the specific time zone you want:
a - 10*3600 which gives UTC time too
strptime gets its parameters from the time string. As such, the time string must contain time zone information.
If you are parsing time strings in a specific time zone, but the time strings that you receive do not have it embedded - then you can add time zone information before passing the time string to srtptime, and asking strptime to parse the time zone offset using %z or name using %Z.
In a nutshell, if you have a time string 08/26/2013 03:30 PM and you want it parsed in the UTC time zone, you would have:
str = '08/26/2013 03:30 PM'
Time.strptime("#{str} UTC}", "%m/%d/%Y %I:%M %p %Z")
I have an AWS server that runs daily cron jobs reporting on our user base. I want to ensure my report is run for the full day the previous day in MST. Currently I use this as the code for the data quering
Time.new(Time.now.year, Time.now.month, Time.now.day).yesterday.beginning_of_day.in_time_zone('MST)..Time.new(Time.now.year, Time.now.month, Time.now.day).yesterday.end_of_day.in_time_zone('MST)
I read it is bad practice to use Time.now as that is the system (UTC) time? I am wondering if what I am doing is a big no no or if there is a more efficient way?
thank you!
Mountain Standard Time is 7 hours behind UTC, so when you capture all the data points from the day of July 22rd in MST, you want the UTC times to be from 7/22 at 7:00AM UTC to 7/23 at 7:00AM UTC.
I don't think your code is correct because you are calling in_time_zone("MST") after beginning_of_day.
When you run this code on a server that is on UTC, the evaluated times are different:
>> Time.new.yesterday.beginning_of_day.in_time_zone('MST').utc
=> 2013-07-22 00:00:00 UTC
>> Time.new.in_time_zone("MST").yesterday.beginning_of_day.utc
=> 2013-07-22 07:00:00 UTC
Here is how you can determine the start and end times properly:
>> t = Time.new
=> 2013-07-23 19:45:10 +0000
>> start_time = t.in_time_zone("MST").yesterday.beginning_of_day
=> Mon, 22 Jul 2013 00:00:00 MST -07:00
>> end_time = t.in_time_zone("MST").yesterday.end_of_day
=> Mon, 22 Jul 2013 23:59:59 MST -07:00
When we convert the start and end times to UTC, we get the desired result.
>> start_time = t.in_time_zone("MST").yesterday.beginning_of_day.utc
=> 2013-07-22 07:00:00 UTC
>> end_time = t.in_time_zone("MST").yesterday.end_of_day.utc
=> 2013-07-23 06:59:59 UTC
I don't know what you are trying to do, but
Time.new(Time.now.year, Time.now.month, Time.now.day)
is definitely a terrible code fragment. For example, if the time lag between the execution time of Time.now.year and that of Time.now.month overlaps the moment of the change of the year, then the time object created with the main Time.new will be neither of the two moments. If you want to get the current time, just do
Time.new
or
Time.now
If you are trying to create a time range calculated out of a single time, then whatever your code should be, create time only once:
t = Time.now
and use that in the rest of your code:
t.some_method..t.some_other_method
I'm trying to figure out how to extract dates from unstructured text using Ruby.
For example, I'd like to parse the date out of this string "Applications started after 12:00 A.M. Midnight (EST) February 1, 2010 will not be considered."
Any suggestions?
Try Chronic (http://chronic.rubyforge.org/) it might be able to parse that otherwise you're going to have to use Date.strptime.
Assuming you just want dates and not datetimes:
require 'date'
string = "Applications started after 12:00 A.M. Midnight (EST) February 1, 2010 will not be considered."
r = /(January|February|March|April|May|June|July|August|September|October|November|December) (\d+{1,2}), (\d{4})/
if string[r]
date =Date.parse(string[r])
puts date
end
Also you can try a gem that can help find date in string.
Exapmle:
input = 'circa 1960 and full date 07 Jun 1941'
dates_from_string = DatesFromString.new
dates_from_string.get_structure(input)
#=> return
# [{:type=>:year, :value=>"1960", :distance=>4, :key_words=>[]},
# {:type=>:day, :value=>"07", :distance=>1, :key_words=>[]},
# {:type=>:month, :value=>"06", :distance=>1, :key_words=>[]},
# {:type=>:year, :value=>"1941", :distance=>0, :key_words=>[]}]