Syntax:
set xdata time set ydata time set zdata time set x2data time set y2data time
To turn the x axis data back to the default:
set xdata
See set timefmt to tell gnuplot how to read date or time data. The date/time is converted to seconds from start of the century. There is currently only one timefmt, which implies that all the date/time columns must confirm to this format. Specification of ranges should be supplied as quoted strings according to this format to avoid interpretation of the date/time as an expression.
The function ``strftime'' (type ``man strftime'' on unix to look it up) is used to print ticmark labels. gnuplot tries to figure out a reasonable format for this unless the set format x ``string'' has supplied something that does not look like a decimal format (more than one '%' or neither %f nor %g).