dates/clock_and_calendar.rb

tests/_examples/dates/clock_and_calendar.rb in the metorex repository.

# A DateTime is a calendar day with a time of day and an offset from UTC. The
# time is held as an exact fraction of a day, so arithmetic loses nothing.
require 'date'

meeting = DateTime.new(2012, 12, 24, 13, 45, 30, "+03:00")

p meeting.year
p meeting.month
p meeting.day
p meeting.hour
p meeting.min
p meeting.sec
p meeting.sec_fraction
p meeting.offset
p meeting.zone
p meeting.to_s
p meeting.day_fraction

p meeting.new_offset("-05:00").to_s
p meeting.new_offset(0).to_s
p meeting.to_date.to_s
p meeting.to_date.class
p DateTime.new(2012, 12, 24).to_date.to_datetime.to_s

p meeting.strftime("%Y-%m-%d %H:%M:%S %z")
p meeting.strftime("%I:%M %p")
p meeting.strftime("%A, %-d %B %Y")
p meeting.strftime("%::z")
p DateTime.new(2001, 2, 3, 4, 5, 6.25).strftime("%H:%M:%S.%6N")
p DateTime.new(2001, 2, 3, 4, 5, 6.25).strftime("%L")

p DateTime.parse("2012-11-08T15:43:59").to_s
p DateTime.strptime("2012-11-08 15:43:59", "%Y-%m-%d %H:%M:%S").to_s
p DateTime.iso8601("2018-01-01").to_s

# A day is one unit, so a quarter of a day is six hours.
p (meeting + Rational(1, 4)).to_s
p (meeting - Rational(1, 2)).to_s
p (DateTime.new(2012, 1, 2) - DateTime.new(2012, 1, 1))
p (DateTime.new(2012, 1, 1, 6) - DateTime.new(2012, 1, 1))
p DateTime.new(2012, 1, 1, 6) > DateTime.new(2012, 1, 1)

# An hour of 24 names midnight on the day after.
rolled = DateTime.new(2012, 12, 24, 24)
p rolled.day
p rolled.hour

moment = Time.utc(2012, 12, 31, 23, 58, 59)
p moment.to_datetime.to_s
p moment.to_date.to_s
p DateTime.new(2012, 12, 31, 23, 58, 59).to_time.utc.to_s

Output:

2012
12
24
13
45
30
(0/1)
(1/8)
"+03:00"
"2012-12-24T13:45:30+03:00"
(1651/2880)
"2012-12-24T05:45:30-05:00"
"2012-12-24T10:45:30+00:00"
"2012-12-24"
Date
"2012-12-24T00:00:00+00:00"
"2012-12-24 13:45:30 +0300"
"01:45 PM"
"Monday, 24 December 2012"
"+03:00:00"
"04:05:06.250000"
"250"
"2012-11-08T15:43:59+00:00"
"2012-11-08T15:43:59+00:00"
"2018-01-01T00:00:00+00:00"
"2012-12-24T19:45:30+03:00"
"2012-12-24T01:45:30+03:00"
(1/1)
(1/4)
true
25
0
"2012-12-31T23:58:59+00:00"
"2012-12-31"
"2012-12-31 23:58:59 UTC"