The GeoTimer application was designed to convert the dates / times between Gregorian format, GPS time and the Modified Julian Date (MJD) as soon as some valid values are entered. The maximum resolution is one milli-second. The program always starts with the actual system date/time.

A green ball shows you always where the last value was entered via keyboard.

The tool 'Time Span Calculation' gives you the possibility to calculate the time span between two dates/times (here, the resolution is always one second!).

There are some restrictions:

- The earliest possible Gregorian year is 1900.

- The earliest possible GPS date/time is Jan., 6th, 1980 (there, the GPS time starts with 0).

- The earliest MJD day possible is 15020 according to the restriction of the Gregorian date.

- The maximum time span calculation is over 24850 days or about 68 years.

More remarks:

- If you want to get the Julian Date (JD) out of the Modified Julian Date (MJD) use:

JD = MJD + 2.400.000,5 days

- The MJD refers to midnight and the JD to noon.

- If the entry 'n/a' is displayed, a computation for this time scale is not available.

- Week-of-year calculation: The weeks start with Monday and end with Sunday. The first week of a year is that, that contains the 4th of Jan. So it is possible, that a week belongs to the last or to the next year. Most of the years have 52 weeks some have 53.

- GPS week calculation: The GPS week is always computed starting with 0 up to an arbitrary value. There is no week-rollover applied, that occurs every 1023 weeks. You can see the number of rollovers in brackets and the corresponding week number behind the input line of the GPS week. (Example: GPS week 1056 has one rollover and corresponds to the week 33 (1). )

- A From-Date/Time could not be directly entered. You always have to enter first somewhere else and then set it by clicking on the given button.