Basically being able to calculate your own (or an alreasy known e.g. GPE = mxhxg) by only specifying the formula, units and unknown quantities, also should be fully re-arrangeable ideally.

1. Differences between timezone
2. What day/time of "A" if "B" is xxxx?

Always got problems find location B day/time if location A at this day/time. E.g. What day/time in Chicago IL, if Nov 1, 8am, ACT Aust?

BTW- good site!

allow it to fill in a terminal parenthesis, e.g., if i type "cos(30" and hit enter, it should evaluate the cosine; or, it should just say "syntax problem" without erasing all my typing and making me start from scratch.

Conversion of DMS / DD for stuff like Lat/Long or survey data

Should be able to export data, should be able to change any line later

This will allow users to write custom script and publish them to shared library, where other users will be able to use them

a calculator with all the trig ratios to avoid tedios algebra and calculatores. all you would need to do is type the length of certain sides, areas, angles and the calculator will do the rest.

The possibility to save favorite currency, either with the person signing in or using currency history.

Mathematical Function

1. Convert date of birth to number of days or hours/minutes/seconds
2. convert remaining retirement years/days
3. Convert Company Joining Date to till date(convert to number of years/days)