/usr/share/libswe/ephe/sedeltat.txt.inactive is in swe-basic-data 1.80.00.0002-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 | # This file allows to make new Delta T known to the Swiss Ephemeris.
# Note, these values override the values given in the internal Delta T
# table of the Swiss Ephemeris.
#
# If you want to use this file, change its file name and remove the
# the extension '.inactive'. As soon as you do so, the values below
# will be used, i.e. they will override the internal Delta T values
# of the Swiss Ephemeris.
#
# Format: year and seconds (decimal)
2007 65.15
2008 65.46
2009 65.78
|