ftp.gettextfile('ReceiveLog_ABC-4444_yyyymmdd.log','upsmi.csv')
Today is 20161103.
How can I get ReceiveLog_ABC-4444_20161102.log?
I want to know if date were 20161201, how to look for 20161130 file?
You can use the Date library to handle this:
require 'date'
date_format = '%Y%m%d'
date = Date.parse('20161103', date_format)
# => #<Date: 2016-11-03 ((2457696j,0s,0n),+0s,2299161j)>
previous_date = date - 1
# => #<Date: 2016-11-02 ((2457695j,0s,0n),+0s,2299161j)>
previous_date.strftime(format)
# => "20161102"
This handles incrementing and decrementing to properly account for the lengths of the months and the start/end of the year.
Related
My timezone is IST, +0530.
It shows the correct zone if I pass arguments with recent years:
Time.new('2000', '02', '29') # => 2000-02-29 00:00:00 +0530
But the zone changes for years like these:
Time.new('1000', '01', '29') # => 1000-01-29 00:00:00 +0553
Time.new('1943') # => 1943-01-01 00:00:00 +0630
Time.new('1871') # => 1871-01-01 00:00:00 +0521
To find out the previous dates, I created a loop:
puts 2_200.times.map { |i| Time.new(i.to_s) }
As I can see for the years in the future, the zone is +0530, but for past centuries, the zone is sometime differs!
Why does the zone differ in the same system?
Why does the zone differ in the same system?
Because time zones change over time.
How to get previous day on UTC time using ruby?
Currently I'm using Time.now.utc.iso8601 to get UTC time format in ruby, I need previous day in same UTC format. Can someone help me with sample code to get previous day?
> Time.now.utc
=> 2015-03-22 19:00:46 UTC
> Time.now.utc - 86400
=> 2015-03-21 19:00:51 UTC
> (Time.now.utc - 86400).iso8601
=> "2015-03-21T19:00:59Z"
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 have a ruby script that checks a provided date, to make sure it is today's date. This is not working when the date provided doesn't have a 2 digit padding for the month. Is there anyway to get ruby to see that as equal? The example is that it says "Date Processed 3/13/2014 is not today's date 03/13/2014!" the difference is in the month - 3 vs 03. Below is the code. ev_val is provided from a csv and it is m/d/yyyy format. It is not provided with a 0 padding, though. Any thoughts?
Thanks!
tnow = Time.now
if ev_val != tnow.strftime("%m/%d/%Y")
log_linemsg = "Date Processed #{ev_val} is not today's date #{tnow.strftime("%m/%d/%Y")}! Processing date must be today's Date!!!\nSTOPPING SCRIPT!!!"
log_line = ["#{$cname}","#{log_linemsg}","","",]
puts log_linemsg
insert_logitems(connection, table_namelog, log_line)
exit
end
require "date"
date_val = Date.parse ev_val
today = Date.today
if today != date_val
log_linemsg = "Date Processed #{ev_val} is not today's date #{today}! Processing date must be today's Date!!!\nSTOPPING SCRIPT!!!"
end
Since you only care about the date portion, I would use Date instead of Time.
Take your input string and parse it into a Date object, then compare it to today's date.
?> date_val = Date.parse('3/13/2014')
=> Thu, 13 Mar 2014
>> date_val == Date.today
=> true
In your example Date.parse(ev_val) != Date.today should work for the comparison.
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.