Maxclock

A high-precision digital astronomical software clock. Version is offering the following modifications: Obliquity polynomial is now selectable, obliquity reference value for epoch 2000 slightly corrected Acoustic signalling (time beeps to computer soundcard) selectable DELTA-T model updated (values derived from IERS C04 Earth orientation data up to Jan. 2004) Documentation encompasses hints for celestial navigation Regarding precession/nutation modelling, the software uses the conventional paradigm and the IAU 1980 lunisolar series. The paradigm outlined by IAU 2000 resolutions will probably be realized in future software versions. In revision 1, a bug regarding leap seconds handling has been fixed now: A negative DUT1 together with an early time instant at the beginning of a day routinely yields an UT1 instant in the day before - as long as UTC has not progressed beyond the magnitude of DUT1. This mechanism had not been computed properly. The error for mean solar time display for zero meridian had been in the order of twice DUT1, other time displays had been in error by fraction of millisecond. As mentioned, IERS-based Delta-T values are included up to Jan. 2004 only and an internal Ephemeris time Algorithm is used from that time on. For the beginning of year 2006 it has been found, that the deviation of the internal algorithm does not exceed 4.0x10-2 seconds when compared to Delta-T values derived from latest IERS C04 data.