diff --git a/test/unit/date/expand-pattern/compare-formats.js b/test/unit/date/expand-pattern/compare-formats.js
new file mode 100644
index 000000000..f9e41212a
--- /dev/null
+++ b/test/unit/date/expand-pattern/compare-formats.js
@@ -0,0 +1,27 @@
+define([
+	"src/date/expand-pattern/compare-formats"
+], function( compareFormats ) {
+
+QUnit.module( "Date Expand Pattern Compare Formats" );
+
+// "Most symbols have a small distance from each other, e.g., M ≅ L; E ≅ c; a ≅ b ≅ B;
+//  H ≅ k ≅ h ≅ K; ..."
+QUnit.test( "should add a small distance on similar patterns", function( assert ) {
+	assert.ok( compareFormats( "MM", "LL" ) > compareFormats( "MM", "MM" ) );
+	assert.ok( compareFormats( "MM", "LLL" ) > compareFormats( "MM", "MMM" ) );
+	assert.ok( compareFormats( "E", "c" ) > compareFormats( "E", "E" ) );
+});
+
+// Numeric (l<3) and text fields (l>=3) are given a larger distance from each other.
+QUnit.test( "should add a larger distance comparing numeric vs text fields", function( assert ) {
+	assert.ok( compareFormats( "MM", "MMM" ) > compareFormats( "MM", "M" ) );
+	assert.ok( compareFormats( "MMM", "MM" ) > compareFormats( "MMM", "MMMMM" ) );
+});
+
+QUnit.test( "should mark not equal things", function( assert ) {
+	assert.equal( compareFormats( "yMd", "d" ), -1 );
+	assert.equal( compareFormats( "MM", "d" ), -1 );
+	assert.equal( compareFormats( "yMMd", "MMM" ), -1 );
+});
+
+});