cmd
+ d
deletes the current line.
cmd
+ shift
+ down/up
simply selects all the text up and down, it doesn't move the current line (would love this as well!)
cmd
+ shift
+ ?
pops up the help in Chrome rather than the keyboard shortcut list
@mais-hatem there's no built-in functions for adding/subtracting dates in JavaScript, but there are libraries, like date-fns or Moment.js
Although after taking a stab at solving your problem, it seems like the biggest issue will be parsing that formula you have for dates. If you can instead enforce a more standardized format for your input, it will reduce amount of code considerably.