6.24. Ruby date & time

The Time class is used in Ruby to represent the date and time. It is based on the system date and time provided by the operating system. This class maynot represent dates before 1970 or after 2038.

This tutorial will familiarize you with all the important concepts of date and time.

6.24.1. Create the current date and time #

Here is a simple example of getting the current date and time:

Example #

#/ Usr/bin/ruby - w # - * - coding: UTF-8- * - time1=Time. newputs
: "+time1. inspect # Time. now has the same function as time2=Time. nowputs" Current time
+time2. inspect

The output of the above instance is as follows:

current time : 2015-09-17 15:23:14 +0800
current time: 2015-09-17 15:23:14 +0800

6.24.2. Get Date & Time components #

We can use Time object to get components for various dates and times. Take a look at the following example:

Example #

#/ Usr/bin/ruby w # - * - coding: UTF-8- * - time=Time. new # Time
The component puts "current time:"+time. inspectputtime. year #=>
Year of date puttime. month #=>Month of date (1 to 12) puttime. day #=>
The day of the month (1 to 31) puttime. wday #=>The day of the week (0
It's Sunday) puttime. yday #=>365: The day of the year puttime. hour #=>23:24
Hourly Puttime. min #=>59puttime. sec #=>59puttime. usec #=>
999999: microsecond puttime. zone #=>"UTC": time zone name

The output of the above instance is as follows:

current time : 2015-09-17 15:24:44 +0800
2015
9
17
4
260
15
24
44
921519
CST

6.24.3. `Time.utc` 、 `Time.gm` and `Time.local` function #

These functions can be used to format dates in standard format, as follows:

#July 82008Time. local (2008,7,8) # July 82008,
09:10am, local time Time. local (2008,7,8,9,10) # July 82008, 09:10
UTCTime. utc (2008,7,8,9,10) # July 82008, 09:10:11 GMT (vs. UTC
Same) Time.gm (2008,7,8,9,10,11)

The following example gets all the components in the array:

[sec,min,hour,day,month,year,wday,yday,isdst,zone]

Try the following example:

Example #

#!/usr/bin/ruby -wtime=Time.newvalues=time.to_apvalues

The output of the above instance is as follows:

[39, 25, 15, 17, 9, 2015, 4, 260, false, "CST"]

The array can be passed to the Time.utc or Time.local function to get the different formats of the date, as follows

Example #

#!/usr/bin/ruby -wtime=Time.newvalues=time.to_aputsTime.utc(*values)

The output of the above instance is as follows:

2015-09-17 15:26:09 UTC

Here is how to get the time, the number of seconds since the Epoch (platformdependent):

#Returns the number of seconds since the era time=Time. now. to_ I # Convert seconds to Time
Object Time. at (time) # Returns the number of seconds since the era, including subtle time=Time. now. to_ F

6.24.4. Time zone and daylight saving time #

You can use the Time object to get all the information about the time zone and daylight saving time, as follows:

Time=Time. new # Here is the explanation for time. zone #=>"UTC": returns the time zone time. utc_ Offset #=>
0: UTC is a 0 second offset from UTC time. zone #=>
PST (or other time zone) time. isdst #=>false: If UTC does not have
DST (Daylight Saving Time) time. utc? #=> True: If in UTC
Time zone time. localtime # Convert to local time zone time. gmtime # Convert back
UTC time. getlocal # Returns a new Time object in the local area time. getutc # Returns UTC
A new Time object in

6.24.5. Format time and date #

There are several ways to format dates and times. The following example demonstrates some of them:

Example #

#!/usr/bin/ruby
-wtime=Time.newputstime.to_sputstime.ctimeputstime.localtimeputstime.strftime("%Y-%m-%d
%H:%M:%S")

The output of the above instance is as follows:

2015-09-17 15:26:42 +0800
Thu Sep 17 15:26:42 2015
2015-09-17 15:26:42 +0800
2015-09-17 15:26:42

6.24.6. Time formatting instruction #

The instructions and methods listed in the following table Time.strftime use it together.

Instruction	Description
% a	An acronym for the day of the week (such as Sun).
% A	The full name of the day of the week (such as Sunday).
% b	An abbreviation for the name of the month (for example, Jan).
% B	The full name of the month (for example, January).
% c	Preferred local date and time representation.
% d	The day ordinal of a month (01 to 31).
% H	The hour ordinal of the day, 24-hour system (00 to 23).
% I	The hour ordinal of the day, the 12-hour system (01 to 12).
% j	The day of the year (001 to 366).
% m	The month of the year (01 to 12).
% M	The minute (00 to 59) of the hour.
% p	Meridian indication (AM or PM).
% S	The second (00 or 60) ordinal of a minute.
% U	The number of weeks in the current year, starting on the first Sunday (as the first day of the first week) (00 to 53).
% W	The number of weeks in the current year, starting on the first Monday (as the first day of the first week) (00 to 53).
% w	The day of the week (Sunday is 0 to 6).
% x	There is only a priority representation of the date and no time.
% X	There is only a priority representation of time and no date.
% y	A year without a century is represented by (00 to 99).
% Y	A year with a century.
% Z	Time zone name.
%%	% characters.

6.24.7. Time algorithm #

You can use your time to do some simple arithmetic, as follows:

Now=Time. now # The current time putsnowpast=now-10 # 10 seconds ago. Time - number=>
Timeputpassfrequency=now+10 # 10 seconds from now. Time+number=>
Timeputsfurturediff=future now #=>10 Time - Time=>Number of seconds putsdiff

The output of the above instance is as follows:

2015-09-17 15:27:08 +0800
2015-09-17 15:26:58 +0800
2015-09-17 15:27:18 +0800
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