Convert a string date format from “17-Nov-2011” to “11/17/11”

Question

I have this code that converts an array of date strings from a format of 17-Nov-2011 to 11/17/11:

def date_convert dates
  months = { \'Jan\' => 1, \'Feb\         


        

Answer 1

With Date#strftime you can format a date. Date.strptime allows you a 'reverse' action: Build a date from string.

When you combine both, you get your result:

puts Date.strptime('17-Nov-2011', '%d-%b-%Y').strftime('%m/%d/%y')

Each %-Parameters is a part of the date string. You need:

For parsing the date string:

• %d: number of the day (17)
• %b: Month with three letters (Nov)
• %Y: Year with 4 digits (2011)

For creating the string:

• %m: Month (11)
• %d: number of the day (17)
• %y: Year with 2 digits (11)

Answer 2

Use the built-in Time.parse and Time#strftime functions.

require 'time'
time = Time.parse("17-Nov-2011")
time.strftime("%m/%d/%y")
# => "11/17/11"

Answer 3

Ruby has a pretty robust set of date and time functions, check out the Date class.

Date.parse("17-Nov-2011").strftime('%m/%d/%y')