The lexical representation for duration is the ISO 8601 extended format:
"-"? + "P" + (nY + "Y")? + (nM + "M" )? + (nD + "D" )? + ("T" (nH + "H")? + (nM + "M")? + (nS + "S")?)?
|"-"||Optional minus sign to represent negative durations. If the sign is omitted a positive duration is indicated.|
|nY||represents the number of years. Must be an unsigned integer.|
|nM||represents the number of months. Must be an unsigned integer.|
|nD||represents the number of days. Must be an unsigned integer.|
|nH||represents the number of hours. Must be an unsigned integer.|
|nM||represents the number of minutes. Must be an unsigned integer.|
|nS||represents the number of seconds, which can include decimal digits represent fractions of seconds.|
P1Y2M3DT10H30M indicates a duration of 1 year, 2 months, 3 days, 10 hours, and 30 minutes.
-P120D indicates a duration of minus 120 days.