From 99080bcc48229658bbb011f0866b7423f564ff55 Mon Sep 17 00:00:00 2001
From: Jessica Kwok <jessicatckwok@gmail.com>
Date: Thu, 3 Jun 2021 10:15:05 -0700
Subject: [PATCH 1/3] Add number of days challenge

---
 DIRECTORY.md            |  1 +
 other/number_of_days.rb | 14 ++++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 other/number_of_days.rb

diff --git a/DIRECTORY.md b/DIRECTORY.md
index d0c4469..5757f9c 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -75,6 +75,7 @@
 
 ## Other
   * [Fisher Yates](https://github.com/TheAlgorithms/Ruby/blob/master/other/fisher_yates.rb)
+  * [Number of Days](https://github.com/TheAlgorithms/Ruby/blob/master/other/number_of_days.rb)
 
 ## Project Euler
   * Problem 1
diff --git a/other/number_of_days.rb b/other/number_of_days.rb
new file mode 100644
index 0000000..4ab6906
--- /dev/null
+++ b/other/number_of_days.rb
@@ -0,0 +1,14 @@
+# Challenge name: Number of Days Between Two Dates
+#
+# Write a program to count the number of days between two dates.
+#
+# The two dates are given as strings, their format is YYYY-MM-DD as shown in the examples. 
+# Example 1:
+# Input: date1 = "2019-06-29", date2 = "2019-06-30"
+# Output: 1
+#
+# Example 2:
+# Input: date1 = "2020-01-15", date2 = "2019-12-31"
+# Output: 15
+#
+# Constraints: The given dates are valid dates between the years 1971 and 2100.
\ No newline at end of file

From e804e6814c1ee91743d9df6e6250bc387fb56fe6 Mon Sep 17 00:00:00 2001
From: Jessica Kwok <jessicatckwok@gmail.com>
Date: Thu, 8 Jul 2021 14:57:00 -0700
Subject: [PATCH 2/3] Add Date.parse solution

---
 other/number_of_days.rb | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/other/number_of_days.rb b/other/number_of_days.rb
index 4ab6906..0a42ad3 100644
--- a/other/number_of_days.rb
+++ b/other/number_of_days.rb
@@ -11,4 +11,24 @@
 # Input: date1 = "2020-01-15", date2 = "2019-12-31"
 # Output: 15
 #
-# Constraints: The given dates are valid dates between the years 1971 and 2100.
\ No newline at end of file
+# Constraints: The given dates are valid dates between the years 1971 and 2100.
+
+
+#
+# Approach 1: Using Date.parse
+# Time complexity: O(1)
+# Space complexity: O(1)
+#
+require 'date'
+
+def number_of_days(date1, date2)
+  beginning_date = Date.parse(date1)
+  end_date = Date.parse(date2)
+  (end_date - beginning_date).to_i.abs
+end
+
+puts number_of_days("2019-06-29", "2019-06-30")
+# => 1
+
+puts number_of_days("2020-01-15", "2019-12-31")
+# => 15
\ No newline at end of file

From 20a79f924b1c7c6370546fb9a5f26ce339d5665b Mon Sep 17 00:00:00 2001
From: Vitor Oliveira <vbrazo@gmail.com>
Date: Sun, 22 Aug 2021 14:20:55 -0700
Subject: [PATCH 3/3] Update number_of_days.rb

---
 other/number_of_days.rb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/other/number_of_days.rb b/other/number_of_days.rb
index 0a42ad3..c0994c7 100644
--- a/other/number_of_days.rb
+++ b/other/number_of_days.rb
@@ -15,10 +15,11 @@
 
 
 #
-# Approach 1: Using Date.parse
+# Approach 1: Using Ruby built-in Date.parse
 # Time complexity: O(1)
 # Space complexity: O(1)
 #
+
 require 'date'
 
 def number_of_days(date1, date2)
@@ -31,4 +32,4 @@ puts number_of_days("2019-06-29", "2019-06-30")
 # => 1
 
 puts number_of_days("2020-01-15", "2019-12-31")
-# => 15
\ No newline at end of file
+# => 15