Skip to contents

The CQL commands R_Date, F14C_Date, C_Date and Date are used to describe individual dated events in a model. R_Date and F14C_Date represent radiocarbon dates expressed in radiocarbon years (the conventional radiocarbon age, CRA) or fraction modern (F14C) respectively. C_Date represents a calendar date. Date directly specifies a date in OxCal's internal format.


cql_r_date(name, date, error)

cql_c_date(name, date, error)

cql_r_f14c(name, date, error)

cql_date(name, date)



Character. Date label(s), usually a lab code.


Numeric. Date or dates expressed in radiocarbon years (cql_r_date()), F14C (cql_f14c_date()), calendar years (cql_c_date()), or OxCal's internal format (cql_date()) See details.


Integer. Uncertainty associated with the date(s).


A cql object, or a list of cql objects if the arguments are vectors.


The era expected for calendar dates (BP or BC/AD) depends on a global option in OxCal, which defaults to BC/AD. BC dates are specified as negative values.

F14C measurements are recommended for modern, "post-bomb" radiocarbon dates (Reimer et al. 2004) .

OxCal's internal date format, used with Date(), is a decimal Gregorian year, for details see:


Reimer PJ, Brown TA, Reimer RW (2004). “Discussion: Reporting and Calibration of Post-Bomb 14C Data.” Radiocarbon, 46(3), 1299--1304. ISSN 0033-8222, 1945-5755, doi:10.1017/S0033822200033154 .

See also

Other CQL functions: cql_boundary(), cql_n(), cql_options(), cql_other, cql_phase(), cql_sequence(), cql(), write_oxcal()