How to Use the Ruby Time Class

09/22/2021

Contents

In this article, you will learn how to use the Ruby Time class.

Using the Ruby Time Class

The Ruby Time class is a built-in class in Ruby that represents a specific moment in time. It provides a range of methods for working with dates and times.

To use the Time class, you first need to require it in your program using:

require 'time'

Creating a Time Object

To create a new Time object, you can use one of the following methods:

  • Time.new: creates a Time object representing the current time

    Time.new

  • Time.local(year, month, day, hour, min, sec): creates a Time object representing a specific local time

    Time.local(2023, 3, 9, 10, 30, 0)

  • Time.utc(year, month, day, hour, min, sec): creates a Time object representing a specific UTC time

    Time.utc(2023, 3, 9, 10, 30, 0)

Retrieving Information from a Time Object

Once you have a Time object, you can retrieve various pieces of information from it, such as the year, month, day, hour, minute, second, and timezone.

time = Time.new # create a Time object representing the current time
puts time.year # prints the current year
puts time.month # prints the current month
puts time.day # prints the current day of the month
puts time.hour # prints the current hour
puts time.min # prints the current minute
puts time.sec # prints the current second
puts time.zone # prints the current timezone

You can also compare Time objects to each other using the comparison operators (<, <=, ==, >=, >).

time1 = Time.local(2023, 3, 9, 10, 30, 0)
time2 = Time.utc(2023, 3, 9, 10, 30, 0)

puts time1 == time2 # prints false
puts time1 < time2 # prints true
puts time1 > time2 # prints false

Formatting a Time Object

You can format a Time object using the strftime method. This method takes a string argument that specifies the format of the output. Some common format codes are:

  • %Y: year
  • %m: month (01..12)
  • %d: day of the month (01..31)
  • %H: hour of the day, 24-hour clock (00..23)
  • %M: minute of the hour (00..59)
  • %S: second of the minute (00..60)
  • %z: time zone as hour and minute offset from UTC (+HHMM or -HHMM)
  
time = Time.new
puts time.strftime("%Y-%m-%d %H:%M:%S %z") # prints something like "2023-03-09 10:30:00 +0900"

Converting a Time Object to Other Formats

You can convert a Time object to other formats using the following methods:

  • to_i: returns the Unix timestamp (the number of seconds since January 1, 1970 UTC)

    time = Time.new
puts time.to_i # prints the current Unix timestamp

  • to_f: returns the Unix timestamp as a floating-point number

    time = Time.new
puts time.to_f # prints the current Unix timestamp as a floating-point number

  • to_s: returns the time in a human-readable format

    time = Time.new
puts time.to_s # prints something like "2023-03
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