diff --git a/core/date.c b/core/date.c
index dde33e6a..aed10f01 100644
--- a/core/date.c
+++ b/core/date.c
@@ -16,3 +16,14 @@ void date_today(struct date *date)
 		date->d_day   = now->tm_mday;
 	}
 }
+
+int date_compare(const struct date *lhs, const struct date *rhs)
+{
+	int ret = lhs->d_year - rhs->d_year;
+	if (ret != 0)
+		return ret;
+	ret = lhs->d_month - rhs->d_month;
+	if (ret != 0)
+		return ret;
+	return lhs->d_day - rhs->d_day;
+}
diff --git a/core/tags/track.cpp b/core/tags/track.cpp
index b7e2489e..fcd228e2 100644
--- a/core/tags/track.cpp
+++ b/core/tags/track.cpp
@@ -104,13 +104,7 @@ void Track :: played()
 
 int Track :: compare_date(const Track *rhs)
 {
-	int ret = _date.d_year - rhs->_date.d_year;
-	if (ret == 0) {
-		ret = _date.d_month - rhs->_date.d_month;
-		if (ret == 0)
-			ret = _date.d_day - rhs->_date.d_day;
-	}
-	return ret;
+	return date_compare(&_date, &rhs->_date);
 }
 
 void Track :: read(file &file)
diff --git a/include/core/date.h b/include/core/date.h
index 1afec771..ca5286ba 100644
--- a/include/core/date.h
+++ b/include/core/date.h
@@ -14,4 +14,13 @@ struct date {
 /* Set the provided date structure to today's date. */
 void date_today(struct date *);
 
+/*
+ * Compare two dates.
+ *
+ * if ret < 0: lhs < rhs.
+ * if ret = 0: lhs == rhs.
+ * if ret > 0: lhs > rhs.
+ */
+int date_compare(const struct date *, const struct date *);
+
 #endif /* OCARINA_CORE_DATE_H */
diff --git a/tests/core/date.c b/tests/core/date.c
index 076b0966..8a48a36f 100644
--- a/tests/core/date.c
+++ b/tests/core/date.c
@@ -25,6 +25,36 @@ void test_date()
 	test_equal(date.d_day,   today->tm_mday);
 }
 
+void test_compare()
+{
+	struct date a = {
+		.d_year  = 2015,
+		.d_month = 6,
+		.d_day   = 17,
+	};
+	struct date b = {
+		.d_year  = 2010,
+		.d_month = 12,
+		.d_day   = 10,
+	};
+
+	/* Check year comparison. */
+	test_equal(date_compare(&a, &b),  5);
+	test_equal(date_compare(&b, &a), -5);
+
+	/* Check month comparison. */
+	b.d_year = a.d_year;
+	test_equal(date_compare(&a, &b), -6);
+	test_equal(date_compare(&b, &a),  6);
+
+	/* Check day comparison. */
+	b.d_month = a.d_month;
+	test_equal(date_compare(&a, &a),  0);
+	test_equal(date_compare(&a, &b),  7);
+	test_equal(date_compare(&b, &a), -7);
+}
+
 DECLARE_UNIT_TESTS(
 	UNIT_TEST("Date", test_date),
+	UNIT_TEST("Date Comparison", test_compare),
 );