Pull request for issue #19

[google-labs-jules]

Fixes #19

[github-actions]

This PR adds new date and time variables for webhooks. The implementation is correct, but there is a minor performance issue due to multiple calls to Date and Date.now(). I've added a comment with a suggestion to refactor this for better performance and consistency.

[github-actions]

low: For efficiency and consistency, it's better to avoid multiple calls to Date.now() and new Date(). You can get the timestamp and ISO string once and reuse them.

A more efficient way to write this would be to declare now and isoNow variables before the placeholders object.

const now = Date.now();
const isoNow = new Date(now).toISOString();
//...
"{{currentUnixTimestamp}}": Math.floor(now / 1000),
"{{currentUnixTimestampMiliseconds}}": now,
"{{currentIsoDate}}": isoNow.slice(0, 10),
"{{currentIsoDateTime}}": isoNow,

This would require refactoring the surrounding code slightly, but would improve performance and make the code cleaner.