I don't understand why the following Ruby 2.4 code fails:
irb(main):006:0> require 'date'
=> false
irb(main):007:0> fmt = "%-m/%-d/%Y %-l:%M:%S %p"
=> "%-m/%-d/%Y %-l:%M:%S %p"
irb(main):008:0> DateTime.now.strftime(fmt)
=> "1/30/2018 7:42:44 AM"
irb(main):009:0> DateTime.strptime("1/30/2018 7:42:44 AM", fmt)
ArgumentError: invalid date
from (irb):9:in `strptime'
from (irb):9
from /usr/local/bin/irb:11:in `<main>'
irb(main):010:0>
The datetime format works when I format a date, but the same format string fails when I try to parse a date string in that format.
Its because strptime doesn't support the flags in the format you are using, have a look at http://ruby-doc.org/stdlib-2.4.2/libdoc/date/rdoc/DateTime.html#method-c-strptime
The error is because the format fmt you have provided doesn't match the DateTime string you have provided.
Change your format from
fmt = "%-m/%-d/%Y %-l:%M:%S %p"
into
fmt = "%m/%d/%Y %l:%M:%S %p"
Hope this helps.
Related
I need to format a string to date:
date = DateTime.parse("05/15/2017")
formatted_date = date.strftime('%m/%d/%Y')
puts formatted_date
But I'm getting an error:
`parse': invalid date (ArgumentError)
And if I try to parse 15/05/2017 then it works.
How to parse 05/15/2017 into %m/%d/%Y format?
It is the first line that raises the error, because Date.parse doesn't know how to handle the string "05/15/2016". Use Date.strptime instead and tell Ruby how to read the string:
DateTime.strptime('05/15/2017', '%m/%d/%Y')
#=> #<DateTime: 2017-05-15T00:00:00+00:00 ((2457889j,0s,0n),+0s,2299161j)>
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!
Why is 'time' being returned as an invalid date?
val = "9/22/2011 4:23 AM"
time = DateTime.parse(val).strftime("%Y-%m-%d %H:%M:%S").to_datetime
#at breakpoint: time = 2011-09-22T04:23:00+00:00 as a DateTime Object
#form_entry.storage_datetime = time # crashes here with invalid date
If it helps, I'm using gem mysql 2.8.1 and Ruby 1.9.2. Thanks
I got an ArgumentError on line two; couldn't create the DateTime object in the first place.
Try using strptime instead:
val = "9/22/2011 4:23 AM"
DateTime.strptime(val, "%m/%d/%Y %H:%M %p")
=> #<DateTime: 2011-09-22T04:23:00+00:00 (3536390423/1440,0/1,2299161)>
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.