Update snippet descriptions

snippets/isWeekday.md

@@ -3,10 +3,10 @@ title: isWeekday
 tags: date,beginner
 ---
 
-Results in a boolean representation of a specific date.
+Checks if the given date is a weekday.
 
-- Pass the specific date object firstly.
-- Use `Date.prototype.getDay()` to check weekday by using a modulo operator and then returning a boolean.
+- Use `Date.prototype.getDay()` to check weekday by using a modulo operator (`%`).
+- Omit the argument, `d`, to use the current date as default.
 
 ```js
 const isWeekday = (d = new Date()) => d.getDay() % 6 !== 0;