Allow Closure at min and max date

PR Summary 📑

Added the power of 'Closure' 🧩 In this update, we're making use of something called 'Closure' - essentially a fancy term for a function that can remember the environment in which it was created, which is pretty neat! This was added at the very top of the file to signal that we want to use this special functionality.
Levelled Up $maxDate and $minDate 🚀 We revamped the type of $maxDate and $minDate properties. They've now leveled up to include Closure. This basically means they're more flexible now and can do more stuff than before!
Tweaked maxDate() and minDate() methods for more power 💪 Both the maxDate() and minDate() methods have received a tweak. They now can accept Closure as an argument. This means they can better adapt and offer more precise results. Ingenious modifications here are boosting the program's ability to deal with dates.

Let's continue making the code world a better place! 😄🌏✨