DateTime#+ mystifications

ruby-talk
1

DateTime objects supports adding, right?

I thought so and tested this:

···

#######

require 'parsedate'
require 'date'

dates = [
'2005-04-08 10:48:53.577',
'2005-04-08 11:18:53.577',
'2005-04-08 11:48:53.577',
'2005-04-08 12:18:53.577',
'2005-04-08 12:48:53.577',
'2005-04-08 13:18:53.577',
'2005-04-08 13:48:53.577',
'2005-04-08 14:18:53.577',
]
                    
dates.each{ |d|
  dp = ParseDate::parsedate(d)
  tn = DateTime.new(dp[0],dp[1],dp[2],dp[3],dp[4])
   tn = tn + 3600.0/86400.0
  print d,"; ",tn.ctime,"\n"
}

############

gives this output

2005-04-08 10:48:53.577; Fri Apr 8 11:48:00 2005
2005-04-08 11:18:53.577; Fri Apr 8 12:17:59 2005
2005-04-08 11:48:53.577; Fri Apr 8 12:47:59 2005
2005-04-08 12:18:53.577; Fri Apr 8 13:18:00 2005
2005-04-08 12:48:53.577; Fri Apr 8 13:47:59 2005
2005-04-08 13:18:53.577; Fri Apr 8 13:17:59 2005
2005-04-08 13:48:53.577; Fri Apr 8 13:48:00 2005
2005-04-08 14:18:53.577; Fri Apr 8 15:17:59 2005

And this does look pretty strange when no time in the
right column seem to start with 14.

-- magnus

2

Magnus Bodin wrote:
[...]

  tn = tn + 3600.0/86400.0
print d,"; ",tn.ctime,"\n"

[...]

2005-04-08 13:18:53.577; Fri Apr 8 13:17:59 2005
2005-04-08 13:48:53.577; Fri Apr 8 13:48:00 2005
2005-04-08 14:18:53.577; Fri Apr 8 15:17:59 2005

And this does look pretty strange when no time in the
right column seem to start with 14.

Strange. Looks like Daylight Saving Time starting, but I can't find any place where this happens on 8th April at 14.00...

(It gives the expected output on my machine.)