1 - tptime TPTIME is a calculator-like program that performs conversions between Gregorian date and Julian days, modified Julian days, and truncated Julian days with the different origins used by TOPEX/POSEIDON and other satellites (NASA, CNES, CCSDS).. It also provides date of given cycle, pass of TOPEX/POSEIDON, and vice-versa. License: Shareware OS: Linux Size: 142 KB