All time recording software, including timeSensor LEGAL, save time as decimal values. Conversion from and to hours and minutes format will lead to rounding problems. There are several ways to deal with this in timeSensor LEGAL. This FAQ entry will help you choose which one works best for you. Each entity can use its own method.
Method I: Exact Time Recording
With this method, timeSensor LEGAL will convert time in a decimal value with five digits after the comma.
10 minutes = 0,16667 h
The conversion in a decimal value with five digits after the comma makes accumulated rounding errors negligible, even when you enter a large number of services. If conversion would stop after two digits, this would add up to a significant rounding error and would affect a reconversion into time negatively.
Please note that decimal values are only displayed with two digits after the comma. If you enter "h10" in the time sheet, you will see 0,16 in the cell. The actual value in the cell is 0,16667. The value on an invoice will also only display two digits after the comma. Internal calculations, however, are based on five digits after the comma.
You can see the actual value if you click the cell in the timesheet and select "Qty.":
The advantage of this method is that it gives you high precision when converting and reconverting time into values.
The disadvantage is that it requires discipline in recording time. If you choose this method, you should let timeSensor handle the conversion from minutes to hours. Therefore, use "initials+minutes" (e.g. h10, h70, etc.). Our experience is that this may not work very well in larger firms, where some staff will have the tendency to enter decimal values themselves (0,16 or 0,17). This may again lead to some errors in rounding.
Method II: Time Recording With Timetables
With this method, each time is converted according to a defined table into a decimal value with two digits after the comma. There are different tables for that. timeSensor uses two different tables as shown below. One is referred to in Germany as the "Industrieminute" (http://de.wikipedia.org/wiki/Industrieminute), while the other one is referred to as the UDR table.
A14ENG_02_Excel SHEET Industry Minute
A14ENG_03_Excel Sheet UDR
This method has easiness on its side.
The downside is that it might lead to rounding errors over time, though they tend to even out.
Method III: Rounding Up Every 6 Minutes
With this method, time is rounded up in 6-minute increments. Decimal values increase by 0,1 hour. This excludes accumulated rounding errors entirely.