Every so often, our support department will get an email asking about how Legal Billing does the math for time slips. One thing computers are better at than anything else is doing math, even when that means working with very precise numbers with many decimal places. These decimal places can become necessary when trying to fit two different numbering systems together (100 cents in a dollar but 60 minutes in an hour) with the greatest precision possible.
While your columns in Legal Billing show time lengths up to two decimal places, this is only rounding for your visual benefit, just as with the dollars and cents being rounded to the penny. Legal Billing is using the actual number with full precision to calculate the actual number of hours, times the rate. Same for any calculations on tax.
If you want to avoid rounding questions like this (since hours are based on 60 minutes, not 100 minutes like a decimal system), you can set a minimum billing increment in the program settings to force all time to be charged as exact and even tenths of an hour.
If you had an item you were billing for 5 minutes with no minimum increment, the length of time is actually .083333333333333333333333333333333 (to infinity), rounded to just .08 for display purposes. At any hourly rate of $200 per hour, 5 minutes of work would then be $16.6666666666666666666666666666666666666666 (to infinity) or $16.67 when rounded to the nearest penny.
If you choose instead to bill in a minimum of 6 minutes, this particular example would increase the 5 to the nearest multiple of 6 or exactly 6 minutes or .10 hours in this case. At a rate of $200 per hour, it would then have shown an amount of $22.50 but also would not be affected by any rounding necessities.
Any taxes applied would also use the same high precision numbers with more decimal point places than can be shown.
If you want to set a minimum billing increment, you can go to File, then Settings, and look for the Billing adjustment section on the right. Setting this minimum number of minutes to 6 means any new time slips with a part of a 6 minute time period (1 second to 5 minutes 59 seconds) will be saved as a full 6 minutes. When displayed as a decimal part of an hour, 6 minutes is .1 hours, a nice even number not requiring any additional decimal places or extra precision.
Please note that the minimum billing increment (should you choose to use this feature) only applies to new time slips. If you choose to edit an existing time slip and change the amount of time billed, you will have full control to bill for an exact time, for better or worse as far as fractional parts of an hour that ends up being.
This help article applies to Legal Billing 7 or newer