I have a string like this: "20130429130501" (It is date and time with chomped UTC zone info (.0Z); it can be represented like %Y%m%d%H%M%S). I was trying DateTime.parse and DateTime.strptime without success. Is it possible to convert it to DateTime class object?
require "date"
DateTime.parse("20130429130501", "%Y%m%d%H%M%S")
# => #<DateTime: 2013-04-29T13:05:01+00:00 ((2456412j,47101s,0n),+0s,2299161j)>
Related
I am getting a date as a string like below:
"September 1998"
I tried like Date.parse("September 1998"), but it did not work.
How do I convert it into a ruby date object which returns string in above format?
Date.strptime('September 1998', '%B %Y'). However, this will represent September 1st 1998, because date objects represent, well, dates.
You could use the chronic gem:
require 'chronic'
t = Chronic.parse('September 1998', :guess => true) #returns a Time object
=> 1998-09-01 00:00:00 -0700
t.to_date #convert to Date object
=> <Date: 1998-09-16 ((2451073j,0s,0n),+0s,2299161j)>
Chronic was created by Tom Preston-Werner, who also co-created Github.
Just prepend the missing "1 ":
str ="September 1998"
p Date.parse("1 " + str) # => #<Date: 1998-09-01 ((2451058j,0s,0n),+0s,2299161j)>
So I'm parsing this string from AIX's errpt - to convert it into epoch - and it doesn't seem to be respecting the Hour and Minute part of the string.
So the string is: 1108095913 (MMDDHHMMYY) .. but when I do my strptime to convert it to a date object, and then format it how I want, it completely zero'd out my hour and minute.
Am I missing something?
irb(main):039:0> Date.strptime("1108095913", "%m%d%H%M%y").strftime('%m/%d/%y %H:%M')
=> "11/08/13 00:00"
You should use Time.strptime instead of Date method, Date removes hours and minutes
1.9.3-p429 :005 > Time.strptime("1108095913", "%m%d%H%M%y").strftime('%m/%d/%y %H:%M')
=> "11/08/13 09:59"
Use DateTime instead of Date:
irb(main):002:0> require 'date'
=> true
irb(main):003:0> DateTime.strptime("1108095913", "%m%d%H%M%y").strftime('%m/%d/%y %H:%M')
=> "11/08/13 09:59"
The reason is DateTime handles date and time, both and Date only handles date.
Hope this helps!
I have a date string 20101129220021, so I will use
require 'date'
d = DateTime.parse('20101129220021')
This part works fine, and I get a date, which is in UTC.
My question is, how can I convert this into my local time? I tried many methods like extracting the time part using d.to_time and manipulate the result, but it didn't work. As far as I know, DateTime object is immutable. Can I please get some help?
irb(main):001:0> require "date"
=> true
irb(main):002:0> d = DateTime.parse('20101129220021')
=> #<DateTime: 2010-11-29T22:00:21+00:00 (70719276007/28800,0/1,2299161)>
irb(main):003:0> d.to_time
=> 2010-11-30 00:00:21 +0200
ruby 1.9.2p180 (2011-02-18)
You can add a rational fraction based on the timezone to get the local time.
require 'date'
# Make this whatever your zone is. Using UTC +0300 here.
ZONE = 3
d = DateTime.parse('20101129220021') + Rational(ZONE,24)
d.to_s # => "2010-11-30T01:00:21+00:00"
How do I create a Ruby date object from the following string?
DD-MM-YYYY
Date.parse('31-12-2010')
Alternatively Date#strptime(str, format).
Because in the USA they get the dates backwards, it's important not to simply use Date.parse() because you'll find 9/11/2001 can be 11 September 2001 in the USA and 9 November 2001 in the rest of the world. To be completely unambiguous use Date::strptime(your_date_string,"%d-%m-%Y") to correctly parse a date string of format dd-mm-yyyy.
Try this to be sure:
>irb
>> require 'date'
=> true
>> testdate = '11-09-2001'
=> "11-09-2001"
>> converted = Date::strptime(testdate, "%d-%m-%Y")
=> #<Date: 4918207/2,0,2299161>
>> converted.mday
=> 11
>> converted.month
=> 9
>> converted.year
=> 2001
For other strptime formats see http://pubs.opengroup.org/onlinepubs/009695399/functions/strptime.html
Also I always make sure I set my base timezone to :utc if my website is going to be handling any dates, and use Javascript on the client side to display local times.
You can use Time#parse.
Time.parse("20-08-2010")
# => Fri Aug 20 00:00:00 +0200 2010
However, because Ruby could parse the date as "MM-DD-YYYY", the best way is to go with DateTime#strptime where you can specify the input format.
If you have control over the format of the date in the string, then Date.parse works fine internationally with strings in YYYY-MM-DD (ISO 8601) format:
Date.parse('2019-11-20')
I find this approach simpler since it avoid having to specify the date format for the parser:
date1 = Time.local(2012, 1, 20, 12, 0, 0).to_date
Like this You can get time Object from a string like this:
t = Time.parse "9:00 PM"
=> 2013-12-24 21:00:00 +0530
t = Time.parse "12:00 AM"
=> 2013-12-24 00:00:00 +0530
But Ruby parsing this as a Date!
So you can use the column as a string.
add_column :table_name, :from, :string, :limit => 8, :default => "00:00 AM", :null => false
add_column :table_name, :to, :string, :limit => 8, :default => "00:00 AM", :null => false
And you can assign string object to the attribute,
r.from = "05:30 PM"
r.save
And parse the string for getting time object,
Time.zone.parse("02:00 PM")
Not necessary for this particular string format, but best string to time parsing utility I know is Chronic which is available as a gem and works for about 99.9% of usecases for human formatted dates/times.
If I have d = DateTime.now, how do I convert 'd' into UTC (with the appropriate date)?
DateTime.now.new_offset(0)
will work in standard Ruby (i.e. without ActiveSupport).
d = DateTime.now.utc
Oops!
That seems to work in Rails, but not vanilla Ruby (and of course that is what the question is asking)
d = Time.now.utc
Does work however.
Is there any reason you need to use DateTime and not Time? Time should include everything you need:
irb(main):016:0> Time.now
=> Thu Apr 16 12:40:44 +0100 2009
Unfortunately, the DateTime class doesn't have the convenience methods available in the Time class to do this. You can convert any DateTime object into UTC like this:
d = DateTime.now
d.new_offset(Rational(0, 24))
You can switch back from UTC to localtime using:
d.new_offset(DateTime.now.offset)
where d is a DateTime object in UTC time. If you'd like these as convenience methods, then you can create them like this:
class DateTime
def localtime
new_offset(DateTime.now.offset)
end
def utc
new_offset(Rational(0, 24))
end
end
You can see this in action in the following irb session:
d = DateTime.now.new_offset(Rational(-4, 24))
=> #<DateTime: 106105391484260677/43200000000,-1/6,2299161>
1.8.7 :185 > d.to_s
=> "2012-08-03T15:42:48-04:00"
1.8.7 :186 > d.localtime.to_s
=> "2012-08-03T12:42:48-07:00"
1.8.7 :187 > d.utc.to_s
=> "2012-08-03T19:42:48+00:00"
As you can see above, the initial DateTime object has a -04:00 offset (Eastern Time). I'm in Pacific Time with a -07:00 offset. Calling localtime as described previously properly converts the DateTime object into local time. Calling utc on the object properly converts it to a UTC offset.
Try this, works in Ruby：
DateTime.now.to_time.utc
You can set an ENV if you want your Time.now and DateTime.now to respond in UTC time.
require 'date'
Time.now #=> 2015-11-30 11:37:14 -0800
DateTime.now.to_s #=> "2015-11-30T11:37:25-08:00"
ENV['TZ'] = 'UTC'
Time.now #=> 2015-11-30 19:37:38 +0000
DateTime.now.to_s #=> "2015-11-30T19:37:36+00:00"
In irb:
>>d = DateTime.now
=> #<DateTime: 11783702280454271/4800000000,5/12,2299161>
>> "#{d.hour.to_i - d.zone.to_i}:#{d.min}:#{d.sec}"
=> "11:16:41"
will convert the time to the utc. But as posted if it is just Time you can use:
Time.now.utc
and get it straight away.