Calculate last day of month

Unpacking the magic

The date object constructor new Date(year, month + 1, 0) is kind of like finding the last cookie in the jar by reaching for where the next cookie should've been. The day value of 0 tells JavaScript, "Hey, go back a day!" and thus, you land on the last day of the desired month. It's this trick that standardize across browsers, making this method reliable.

Browser compatibility checks

To ensure our cookie trick works everywhere, check your code in different browsers. Even though the ECMAScript specification has harmonized the implementation, it's always prudent to verify in real-world conditions.

For the performance geeks

Bitwise operations come into play when we need to carry out operations at the binary level, like calculating leap years. While they are not directly applicable to our current problem, knowing they exist could be a crown jewel for complex date calculations.

The specifics

The importance of toString

When logging dates in console, remember toString() is like your favorite shirt- looks different depending on the light (or in this case, the browser and locale). The date hasn't changed, just its representation.

Ensuring consistent results

Always aim for uniformity. Consider using toISOString() for a global, uniform representation in UTC.

Beyond simplicity

For handling complex scenarios, alternative methods and understanding intermediate dates are key. Testing these across different browsers ensures code solidity.

Timezone trouble

Timezones are like the hot sauce of coding - a little bit can drastically change the outcome. Be careful with local dates and always consider the user's local timezone.

Performance insights

For those interested in maximum efficiency, JSPerf tests can help you keep abreast of any new, possibly quicker, ways to compute date manipulation operations.