All stored epochs are GPS time¶

RINEX observation files, SBF and the orbit and clock products are GPS time natively, receivers sample on whole GPS seconds and files are named by GPS day. Storing UTC would move epochs 18 s off the sampling grid and across day boundaries. Readers convert other scales on read (NMEA from UTC) and record the scale; a RINEX file that declares another time scale is refused, and so is an append to a store written without a recorded time scale.

Consequences¶

The leap second table ends at the last announced IERS Bulletin C and raises after it; extend it with each new bulletin.