Date invalid Rails leap year - ruby-on-rails

A person was born in 1988 Feb 29 a leap year. How to define this date - 1 day(Feb 28) when the year is not leap?
def valid_date
d = DateTime.parse("Feb. 29")
rescue ArgumentError
d = "Invalid Date"
end

date = 'Feb. 29'
begin
DateTime.parse(date)
rescue ArgumentError
DateTime.parse('Feb. 28') if date == 'Feb. 29'
end

Related

How to get start and end date from quarters?

I am building a rails 5 app.
I need to be able to get the dates that is from a current quarter. With that I mean the user will provide me with a selected quarter (1 to 4) and I will convert that number to a start and end date for that selected quarter. How can I do that?
This is how I tried it but it is good?
def quarter_date(quarter, year)
if quarter == 1
where(date_at: Time.parse("01-01-#{year}")..Time.parse("01-03-#{year}"))
elsif quarter == 2
where(date_at: Time.parse("01-04-#{year}")..Time.parse("01-06-#{year}"))
elsif quarter == 3
where(date_at: Time.parse("01-07-#{year}")..Time.parse("01-09-#{year}"))
elsif quarter == 4
where(date_at: Time.parse("01-10-#{year}")..Time.parse("01-12-#{year}"))
end
end
You mean something like this?
require 'date'
today = Date.today
=> #<Date: 2018-07-02 ((2458302j,0s,0n),+0s,2299161j)>
year = today.year
=> 2018
input = 3
start_date = Date.new(2018, input * 3 - 2, 1)
=> #<Date: 2018-07-01 ((2458301j,0s,0n),+0s,2299161j)>
end_date = Date.new(2018, input * 3 + 1, 1) - 1
=> #<Date: 2018-09-30 ((2458392j,0s,0n),+0s,2299161j)>
It returns the start and end dates for the given quarter of current year.
Update
Updated with method from your attempt:
def quarter_date_range(quarter, year)
start_date = Time.parse("#{year}-#{quarter * 3 - 2}-1")
end_date = (start_date + 2.months).end_of_month
where(date_at: start_date..end_date)
end

ruby date format from date A to date B

I just wonder how the date period can be written in Ruby?
date_a = Time.at() # <= new
date_b = Time.at() # <= old
I'd love to have something like:
September 1 - 30, 2016
Also it needs to be considered the year.
(Ex. if it's in January,
It should be December 25 2016 - January 25 2017)
You could do something like this
def format_dates(*dates)
date1, date2 = dates.sort
return "#{date1.strftime("%B %d %Y")} if date1 == date2
if date1.year == date2.year
if date1.month == date2.month
"#{date1.strftime("%B")} #{date1.day} - #{date2.day}, #{date1.year}"
else
"#{date1.strftime("%B %d")} - #{date2.strftime("%B %d")}, #{date1.year}"
end
else
"#{date1.strftime("%B %d %Y")} - #{date2.strftime("%B %d %Y")}"
end
end
p format_dates(Date.parse('25/12/2016'), Date.parse('25/01/2017'))
# => "December 25 2016 - January 25 2017"
p format_dates(Date.parse('25/12/2016'), Date.parse('25/01/2016'))
# => "January 25 - December 25, 2016"

Ruby: Calculate time difference between 2 times

I want to calculate the difference between 2 times.
start_time: 22:00 (Rails interprets this as 2015-12-31 22:00:00 +0100)
second_time: 02:00 (Rails interprets this as 2015-12-31 02:00:00 +0100). The second time is 4 hours later, so in the next day. Is there a way to calculate this difference?
I can not simply do this: second_time - first_time, because this gives me a difference of 22 hours instead of 4 hours.
Edit:
Some background information:
A job is starting at 22:00 and ending the next day at 02:00. Because i fill in the form of this job only times, this times for the above 2 values are 2015-12-31 22:00:00 +0100 and 2015-12-31 02:00:00 +0100. I don't want the user to fill in the time including the date. The real difference between the times should be 4 hours.
So what i actually want is calculate the difference between 22:00 and 02:00 (in the next day).
I don't understand why you think it should return 4 hours or why it does return 22 hours. 20 hours would be correct for your example:
require 'time'
a = Time.parse('2015-12-31 22:00:00 +0100')
b = Time.parse('2015-12-31 02:00:00 +0100')
a - b
#=> 72000.0 # difference in seconds
(a - b) / 3600
#=> 20.0 # difference in hours
Update: It seems like you are dealing only with the time portion and not with the actual date. And I assume the maximum difference you will have to deal with is 24 hours:
def time_difference(time_a, time_b)
difference = time_b - time_a
if difference > 0
difference
else
24 * 3600 + difference
end
end
a = Time.parse('2015-12-31 22:00:00 +0100')
b = Time.parse('2015-12-31 02:00:00 +0100')
time_difference(a, b) / 3600
# => 4 # hours
a = Time.parse('2015-12-31 02:00:00 +0100')
b = Time.parse('2015-12-31 22:00:00 +0100')
time_difference(a, b) / 3600
# => 20 # hours
Old question but I did a nice method to deal with it:
def time(start,ending)
if start != ending
medidas=["year","month","day","hour","minute","second"]
array=[1970,1,1,0,0,0]
text = ""
Time.at(ending-start).utc.to_a.take(6).reverse.each_with_index do |k,i|
text = "#{text} #{I18n.translate medidas[i].to_sym, count: k-array[i]}"
end
text = text.strip.squish
pos = text.rindex(" ",(text.rindex(" ")-1))
unless pos.nil?
text = text.insert(pos," and")
end
text = text.strip.squish #This shouldn't be needed but just in case
else
"0 seconds"
end
end
Then in config/locales/en.yml I added:
en:
año:
zero: ''
one: '1 year'
other: '%{count} years'
mes:
zero: ''
one: '1 month'
other: '%{count} months'
dia:
zero: ''
one: '1 day'
other: '%{count} days'
hora:
zero: ''
one: '1 hour'
other: '%{count} hours'
minuto:
zero: ''
one: '1 minute'
other: '%{count} minutes'
segundo:
zero: ''
one: '1 second'
other: '%{count} seconds'
So for example when you call:
start = Time.now
ending = start + (60*60)
time(start,ending)
=> "1 hour"
ending = start + (60*60*28)
time(start,ending)
=> "1 day and 4 hours"
ending = start + (53*60*5874)
time(start,ending)
=> "7 months 4 days 4 hours and 42 minutes"
Hope it's useful
I'd write it thusly (before adding data checks), in an attempt to make it self-documenting:
require 'time'
DT_FMT = '%Y-%m-%d %H:%M:%S %z'
SECONDS_PER_DAY = 24*60*60
def hours_elapsed(start_str, finish_str)
start = DateTime.strptime(start_str, DT_FMT).to_time
finish = DateTime.strptime(finish_str, DT_FMT).to_time
finish = same_time_tomorrow(finish) if finish < start
(finish-start)/3600
end
def same_time_tomorrow(time)
time + SECONDS_PER_DAY
end
hours_elapsed '2015-12-31 22:00:00 +0100',
'2015-12-31 02:00:00 +0100'
#=> 4.0
hours_elapsed '2015-12-31 02:00:00 +0100',
'2015-12-31 22:00:00 +0100'
#=> 20.0
It may be better for the arguments of hours_elapsed to be strings containing hours and minutes only, in which case we might rename the method as well. time_elapsed("18:00", "2:30") is an example of how this method might be invoked.
MINUTES_PER_DAY = 24*60
def time_elapsed(start_str, finish_str)
start_mins = time_str_to_minutes(start_str)
finish_mins = time_str_to_minutes(finish_str)
finish_mins += MINUTES_PER_DAY if
finish_mins < start_mins
(finish_mins-start_mins).divmod(60)
end
def time_str_to_minutes(str)
hrs, mins = str.split(':').map(&:to_i)
60 * hrs + mins
end
time_elapsed("8:00", "17:30")
#=> [9, 30]
time_elapsed("18:00", "2:30")
#=> [8, 30]

How to determine the nth weekday for a given month?

This snippet of code determines the date for the nth weekday of a given month.
Example: for the 2nd Tuesday of December 2013:
>> nth_weekday(2013,11,2,2)
=> Tue Nov 12 00:00:00 UTC 2013
Last Sunday of December 2013:
>> nth_weekday(2013,12,'last',0)
=> Sun Dec 29 00:00:00 UTC 2013
I was not able to find working code for this question so I'm sharing my own.
If you are using Rails, you can do this.
def nth_weekday(year, month, n, wday)
first_day = DateTime.new(year, month, 1)
arr = (first_day..(first_day.end_of_month)).to_a.select {|d| d.wday == wday }
n == 'last' ? arr.last : arr[n - 1]
end
> n = nth_weekday(2013,11,2,2)
# => Tue, 12 Nov 2013 00:00:00 +0000
You can use:
require 'date'
class Date
#~ class DateError < ArgumentError; end
#Get the third monday in march 2008: new_by_mday( 2008, 3, 1, 3)
#
#Based on http://forum.ruby-portal.de/viewtopic.php?f=1&t=6157
def self.new_by_mday(year, month, weekday, nr)
raise( ArgumentError, "No number for weekday/nr") unless weekday.respond_to?(:between?) and nr.respond_to?(:between?)
raise( ArgumentError, "Number not in Range 1..5: #{nr}") unless nr.between?(1,5)
raise( ArgumentError, "Weekday not between 0 (Sunday)and 6 (Saturday): #{nr}") unless weekday.between?(0,6)
day = (weekday-Date.new(year, month, 1).wday)%7 + (nr-1)*7 + 1
if nr == 5
lastday = (Date.new(year, (month)%12+1, 1)-1).day # each december has the same no. of days
raise "There are not 5 weekdays with number #{weekday} in month #{month}" if day > lastday
end
Date.new(year, month, day)
end
end
p Date.new_by_mday(2013,11,2,2)
This is also available in a gem:
gem "date_tools", "~> 0.1.0"
require 'date_tools/date_creator'
p Date.new_by_mday(2013,11,2,2)
# nth can be 1..4 or 'last'
def nth_weekday(year,month,nth,week_day)
first_date = Time.gm(year,month,1)
last_date = month < 12 ? Time.gm(year,month+1)-1.day : Time.gm(year+1,1)-1.day
date = nil
if nth.class == Fixnum and nth > 0 and nth < 5
date = first_date
nth_counter = 0
while date <= last_date
nth_counter += 1 if date.wday == week_day
nth_counter == nth ? break : date += 1.day
end
elsif nth == 'last'
date = last_date
while date >= first_date
date.wday == week_day ? break : date -= 1.day
end
else
raise 'Error: nth_weekday called with out of range parameters'
end
return date
end

Ruby: given a date find the next 2nd or 4th Tuesday

I can't seem to find an elegant way to do this...
Given a date how can I find the next Tuesday that is either the 2nd or the 4th Tuesday of the calendar month?
For example:
Given 2012-10-19 then return 2012-10-23
or
Given 2012-10-31 then return 2012-11-13
October November
Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 1 2 3
7 8 9 10 11 12 13 4 5 6 7 8 9 10
14 15 16 17 18 19 20 11 12 13 14 15 16 17
21 22 23 24 25 26 27 18 19 20 21 22 23 24
28 29 30 31 25 26 27 28 29 30
Scroll to the bottom if you just want to see what the end result can look like..
Using code snippets from some date processing work I've done recently in ruby 1.9.3.
Some upgrades to DateTime:
require 'date'
class DateTime
ALL_DAYS = [ 'sunday', 'monday', 'tuesday',
'wednesday', 'thursday', 'friday', 'saturday' ]
def next_week
self + (7 - self.wday)
end
def next_wday (n)
n > self.wday ? self + (n - self.wday) : self.next_week.next_day(n)
end
def nth_wday (n, i)
current = self.next_wday(n)
while (i > 0)
current = current.next_wday(n)
i = i - 1
end
current
end
def first_of_month
self - self.mday + 1
end
def last_of_month
self.first_of_month.next_month - 1
end
end
method_missing Tricks:
I have also supplemented the class with some method missing tricks to map calls from next_tuesday to next_wday(2) andnth_tuesday(2)tonth_wday(2, 2)`, which makes the next snippet easier on the eyes.
class DateTime
# ...
def method_missing (sym, *args, &block)
day = sym.to_s.gsub(/^(next|nth)_(?<day>[a-zA-Z]+)$/i, '\k<day>')
dindex = ALL_DAYS.include?(day) ? ALL_DAYS.index(day.downcase) : nil
if (sym =~ /^next_[a-zA-Z]+$/i) && dindex
self.send(:next_wday, dindex)
elsif (sym =~ /^nth_[a-zA-Z]+$/i) && dindex
self.send(:nth_wday, dindex, args[0])
else
super(sym, *args, &block)
end
end
def respond_to? (sym)
day = sym.to_s.gsub(/^(next|nth)_(?<day>[a-zA-Z]+)$/i, '\k<day>')
(((sym =~ /^next_[a-zA-Z]+$/i) || (sym =~ /^nth_[a-zA-Z]+$/i)) && ALL_DAYS.include?(day)) || super(sym)
end
end
Example:
Given a date:
today = DateTime.now
second_tuesday = (today.first_of_month - 1).nth_tuesday(2)
fourth_tuesday = (today.first_of_month - 1).nth_tuesday(4)
if today == second_tuesday
puts "Today is the second tuesday of this month!"
elsif today == fourth_tuesday
puts "Today is the fourth tuesday of this month!"
else
puts "Today is not interesting."
end
You could also edit method_missing to handle calls such as :second_tuesday_of_this_month, :fourth_tuesday_of_this_month, etc. I'll post the code here if I decide to write it at a later date.
Take a look at Chronic or Tickle, both are gems for parsing complex times and dates. Tickle in particular will parse recurring times (I think it uses Chronic as well).
Check out this gem, you might be able to figure out your answer
https://github.com/mojombo/chronic/
Since you already use Rails, you don't need the includes, but this works in pure Ruby as well for reference.
require 'rubygems'
require 'active_support/core_ext'
d = DateTime.parse('2012-10-19')
result = nil
valid_weeks = [d.beginning_of_month.cweek + 1, d.beginning_of_month.cweek + 3]
if valid_weeks.include?(d.next_week(:tuesday).cweek)
result = d.next_week(:tuesday)
else
result = d.next_week.next_week(:tuesday)
end
puts result
I think you should probably use a library if you're needing to branch out into more interesting logic, but if what you've described is all you need, the code below should help
SECONDS_PER_DAY = 60 * 60 * 24
def find_tuesday_datenight(now)
tuesdays = [*-31..62].map { |i| now + (SECONDS_PER_DAY * i) }
.select { |d| d.tuesday? }
.group_by { |d| d.month }
[tuesdays[now.month][1], tuesdays[now.month][-2], tuesdays[(now.month + 1) % 12][1]]
.find {|d| d.yday > now.yday }
end
Loop through the last month and next month, grab the tuesdays, group by month, take the 2nd and the 2nd last tuesday of the current month (If you actually do want the 4th tuesday, just change -2 to 3) and the 2nd tuesday of the next month and then choose the first one after the provided date.
Here's some tests, 4 tuesdays in month, 5 tuesdays in month, random, and your examples:
[[2013, 5, 1], [2013, 12, 1], [2012, 10, 1], [2012, 10, 19], [2012, 10, 31]].each do |t|
puts "#{t} => #{find_tuesday_datenight(Time.new *t)}"
end
which produces
[2013, 5, 1] => 2013-05-14 00:00:00 +0800
[2013, 12, 1] => 2013-12-10 00:00:00 +0800
[2012, 10, 1] => 2012-10-09 00:00:00 +0800
[2012, 10, 19] => 2012-10-23 00:00:00 +0800
[2012, 10, 31] => 2012-11-13 00:00:00 +0800
I'm sure it could be simplified, and I'd love to hear some suggestions :) (way too late &tired to even bother figuring out what the actual range should be for valid dates i.e. smaller than -31..62)
so here is the code that will resolve a weekday for a given week in a month (what you asked for with little sugar). You should not have problems if you are running inside rails framework. Otherwise make sure you have active_support gem installed. Method name is stupid so feel free to change it :)
usage: get_next_day_of_week(some_date, :friday, 1)
require 'rubygems'
require 'active_support/core_ext'
def get_next_day_of_week(date, day_name, count)
next_date = date + (-date.days_to_week_start(day_name.to_sym) % 7)
while (next_date.mday / 7) != count - 1 do
next_date = next_date + 7
end
next_date
end
I use the following to calculate Microsoft's patch Tuesday date. It was adapted from some C# code.
require 'date'
#find nth iteration of given day (day specified in 'weekday' variable)
findnthday = 2
#Ruby wday number (days are numbered 0-7 beginning with Sunday)
weekday = 2
today = Time.now
todayM = today.month
todayY = today.year
StrtMonth = DateTime.new(todayY,todayM ,1)
while StrtMonth.wday != weekday do
StrtMonth = StrtMonth + 1;
end
PatchTuesday = StrtMonth + (7 * (findnthday - 1))

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