Add isBeforeDate, isAfterDate, isSameDate

snippets/isBeforeDate.md

@@ -0,0 +1,13 @@
+### isBeforeDate
+
+Check if a date is before another date.
+
+Use the less than operator (`<`) to check if the first date comes before the second one.
+
+```js
+const isBeforeDate = (dateA, dateB) => dateA < dateB;
+```
+
+```js
+isBeforeDate(new Date(2010, 10, 20), new Date(2010, 10, 21)); // true
+```