An S4 class to represent time ranges.
Slots
upper,lower
A
numeric
matrix
giving the lower and upper boundaries.names
A
character
vector specifying the name of the events/phases.calendar
A
character
string specifying the chronological scale (either "CE
", "BP
" or "b2k
").hash
A
character
string giving the 32-byte MD5 hash of the original data file.