Rails DateTime gives invalid date sometimes and not others - ruby

I've got a bunch of user-inputted dates and times like so:
date = "01:00pm 06/03/2015"
I'm trying to submit them to a datetime column in a database, and I'm trying to systemize them like this:
DateTime.strptime(date, '%m/%d/%Y %H:%M')
But I consistently get an invalid date error. What am I doing wrong? If I submit the string without strptime the record will save but it sometimes gets the date wrong.
Also, how can I append a timezone to a DateTime object?
Edit:
So .to_datetime and DateTime.parse(date) work for the date string and fail for date2. What's going on?
date2 = "03:30pm 05/28/2015"

Try using to_datetime:
date.to_datetime
# => Fri, 06 Mar 2015 13:00:00 +0000
Also if you read the documentation for DateTime#strptime, here. It states:
Parses the given representation of date and time with the given
template, and creates a date object.
Its important to note that the template sequence must match to that of input string sequence, which don't in your case - leading to error.
Update
Using to_datetime over second example will generate
ArgumentError: invalid date
This is because it expects the date to be in dd-mm-yy format. Same error will be raised for DateTime.parse as to_datetime is nothing but an api for the later. You should use strptime in-case of non-standard custom date formats. Here:
date2 = "03:30pm 05/28/2015"
DateTime.strptime(date2, "%I:%M%p %m/%d/%Y")
# => Thu, 28 May 2015 15:30:00 +0000

date = "01:00pm 06/03/2015"
DateTime.parse(date)
=> Fri, 06 Mar 2015 13:00:00 +0000

You haven't got your parameters in the correct order.
DateTime.strptime(date, '%H:%M%p %m/%d/%Y')
You'll also need to add %p for the am/pm suffix

Related

How to get the same output of departed Date.parse() in groovy?

I have an application that runs the old version of the spring application. The application has the function to create date objects using Date.parse as follows
Date getCstTimeZoneDateNow() {
String dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
def zonedDateString = new Date().format(dateFormat, TimeZone.getTimeZone('CST'))
Date date = Date.parse(dateFormat, zonedDateString)
return date // Tue Oct 18 20:36:12 EDT 2022 (in Date)
}
However, the code above is deprecated. I need to produce the same result.
I read other posts and it seems like Calender or SimpleDateFormatter is preferred.
And I thought SimpleDateFormatter has more capabilities.
This post helped me understand more about what is going on in the following code
SimpleDateFormat parse loses timezone
Date getCstTimeZoneDateNow() {
Date now = new Date()
String pattern = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
SimpleDateFormat sdf = new SimpleDateFormat()
sdf.setTimeZone(TimeZone.getTimeZone('CST'))
// cstDateTime prints times in cst
String cstDateTime = sdf.format(now) // 2022-10-18T20:36:12.088Z (in String)
// JVM current time
Date date = sdf.parse(cstDateTime) // Tue Oct 18 21:36:12 EDT 2022 (in Date)
return date
}
Here my goal is to return the date object that is in the format of Tue Oct 18 20:36:12 EDT 2022
The format is good. However, like the post says, when I do sdf.parse(), it prints in JVM time.
This means, the format is good but the time zone is off.
How can I get the exact same result as before?
It does not have to use SimpleDateFormatter. Could be anything.
Thank you so much for reading and for your time.
Perhaps the important thing is, that the Date is always neutral to the timezone. Given example shows what is to be expected to work from the Java specs:
def format = new SimpleDateFormat()
format.setTimeZone(TimeZone.getTimeZone("CST"))
println new Date()
def date = format.parse(format.format(new Date()))
printf "parsed to %s%n", date
printf "formatted to %s (%s)%n", format.format(date), format.getTimeZone().getDisplayName()
In the output, notice when using the Format and when the toString(), a different time is shown accordingly, which is perfectly fine, since first we format and then parse again in the same format, thus the same time-zone. Later, we use the Date.toString() to output the date, this time using the system default time-zone which is always used when Date.toString() is called. In the output, the time-zone shift is reflected:
Thu Oct 20 09:22:58 EDT 2022
parsed to Thu Oct 20 09:22:00 EDT 2022
formatted to 10/20/22 8:22 AM (Central Standard Time)

Matching Date formatted: "January 17, 2017 10:30 AM" in Ruby

I have been trying to use Date/DateTime to validate that a given date is in the correct format.
str = "January 17, 2017 10:30 AM"
temp = DateTime.strptime(str, '%B %-d, %y %l:%M %p')
but am getting the error
`strptime': invalid date (ArgumentError)
I have been able to split the string into ""January 17," "2017 10:30 AM" and validate it without issue, but I would really like to know why I can't just use strptime on the whole string, or what I am doing wrong if it can be done.
This error is happening because according to the docs of DateTime#strptime:
Parses the given representation of date and time with the given template, and creates a date object. strptime does not support specification of flags and width unlike strftime.
And your format includes a value of %-d which is a width parameter, hence the exception. If you try a basic invocation like:
DateTime.strptime(str, '%B %d, %Y')
you'll see it works. Also, you'll want uppercase-Y for the full 4-digit year.
In a nutshell: you'll need to adjust your format string
This format works fine :
temp = DateTime.strptime(str, '%B %d, %Y %l:%M %p')
#<DateTime: 2017-01-17T10:30:00+00:00 ((2457771j,37800s,0n),+0s,2299161j)>

ROR + Ruby Date From XML API

By using XML API, I got date-time as "2008-02-05T12:50:00Z". Now I wanna convert this text format into different format like "2008-02-05 12:50:00". But I am getting proper way.
I have tried this one :: #a = "2008-02-05T12:50:00Z"
Steps
1. #a.to_date
=> Tue, 05 Feb 2008
2. #a.to_date.strftime('%Y')
=> "2008"
3. #a.to_date.strftime('%Y-%m-%d %H:%M:%S')
=> "2008-02-05 00:00:00
Suggest some thing ?
The to_date method converts your string to a date but dates don't have hours, minutes, or seconds. You want to use DateTime:
require 'date'
d = DateTime.parse('2008-02-05T12:50:00Z')
d.strftime('%Y-%m-%d %H:%M:%S')
# 2008-02-05 12:50:00
Use Ruby's DateTime:
DateTime.parse("2008-02-05T12:50:00Z") #=> #<DateTime: 2008-02-05T12:50:00+00:00 (353448293/144,0/1,2299161)>
From there you can output the value in any format you want using strftime. See Time#strftime for more info.

convert String to DateTime

I need to parse following String into a DateTime Object:
30/Nov/2009:16:29:30 +0100
Is there an easy way to do this?
PS: I want to convert the string above as is. The colon after the year is not a typo. I also want to solve the problem with Ruby and not RoR.
Shouldn't this also work for Rails?
"30/Nov/2009 16:29:30 +0100".to_datetime
DateTime.strptime allows you to specify the format and convert a String to a DateTime.
I have had success with:
require 'time'
t = Time.parse(some_string)
This will convert the string in date to datetime, if using Rails:
"05/05/2012".to_time
Doc Reference: https://apidock.com/rails/String/to_time
I used Time.parse("02/07/1988"), like some of the other posters.
An interesting gotcha was that Time was loaded by default when I opened up IRB, but Time.parse was not defined. I had to require 'time' to get it to work.
That's with Ruby 2.2.
convert string to date:
# without timezone
DateTime.strptime('2012-12-09 00:01:36', '%Y-%m-%d %H:%M:%S')
=> Sun, 09 Dec 2012 00:01:36 +0000
# with specified timezone
DateTime.strptime('2012-12-09 00:01:36 +8', '%Y-%m-%d %H:%M:%S %z')
=> Sun, 09 Dec 2012 00:01:36 +0800
refer to:
https://ruby-doc.org/stdlib-3.1.1/libdoc/date/rdoc/Date.html
in Ruby 1.8, the ParseDate module will convert this and many other date/time formats. However, it does not deal gracefully with the colon between the year and the hour. Assuming that colon is a typo and is actually a space, then:
#!/usr/bin/ruby1.8
require 'parsedate'
s = "30/Nov/2009 16:29:30 +0100"
p Time.mktime(*ParseDate.parsedate(s)) # => Mon Nov 30 16:29:30 -0700 2009
You can parse a date time string with a given timezone as well:
zone = "Pacific Time (US & Canada)"
ActiveSupport::TimeZone[zone].parse("2020-05-24 18:45:00")
=> Sun, 24 May 2020 18:45:00 PDT -07:00

Parsing date from text using Ruby

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=>[]}]

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