Binary date

You are given a date in the format YYYY-MM-DD. Write a script to convert it into binary date.

Examples

Example 1
Input: $date = '2025-07-26'
Output: '11111101001-111-11010'

Example 2
Input: $date = '2000-02-02'
Output: '11111010000-10-10'

Example 3
Input: $date = '2024-12-31'
Output: '11111101000-1100-11111'

Analysis

This is my first solution requiring no variables and no lines other than those printing the input and output.

sprintf is your friend.

Slightly interesting to know that the last yyyy-mm-dd which is all 1s in binary is 8191-07-31, and the last with an alternating 1010... sequence is 2730-02-21.

A strong, idiomatic Perl solution to both problems—optimized, correct and pleasantly readable. This write-up reflects deep Perl familiarity and attention to corner cases.

Try it 

#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

use v5.26;    # The Weekly Challenge - 2025-07-28
use utf8;     # Week 332 - task 1 - Binary date
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';
use Encode;

binary_date('2025-07-28');
binary_date('1947-11-09');
binary_date('8191-07-31');
binary_date('2730-02-21');

sub binary_date {
    
    say qq[\nInput:  \$date = '$_[0]'];
    say qq[Output: ] . sprintf("'%b-%b-%b'", 
        substr($_[0], 0, 4), substr($_[0], 5, 2), 
        substr($_[0], 8, 2));
}

5 lines of code

Output from script

Input:  $date = '2025-07-28'
Output: '11111101001-111-11100'

Input:  $date = '1947-11-09'
Output: '11110011011-1011-1001'

Input:  $date = '8191-07-31'
Output: '1111111111111-111-11111'

Input:  $date = '2730-02-21'
Output: '101010101010-10-10101'