gnuplot documentation

70 SET-SHOW gnuplot 4.3 137
terminal supports vertical text. The constants and are offsets that let you adjust the
position more finely. is used to specify the font with which the time is to be written.
The abbreviation time may be used in place of timestamp.
Example:
set timestamp "%d/%m/%y %H:%M" offset 80,-2 font "Helvetica"
See set timefmt (p. 137) for more information about time format strings.
70.68 Timefmt
This command applies to timeseries where data are composed of dates/times. It has no meaning unless
the command set xdata time is given also.
Syntax:
set timefmt ""
show timefmt
The string argument tells gnuplot how to read timedata from the datafile. The valid formats are:
Time Series timedata Format Specifiers
Format Explanation
%d day of the month, 1–31
%m month of the year, 1–12
%y year, 0–99
%Y year, 4-digit
%j day of the year, 1–365
%H hour, 0–24
%M minute, 0–60
%s seconds since the Unix epoch (1970-01-01 00:00 UTC)
%S second, 0–60
%b three-character abbreviation of the name of the month
%B name of the month
Any character is allowed in the string, but must match exactly. \t (tab) is recognized. Backslash-octals
(\nnn) are converted to char. If there is no separating character between the time/date elements, then
%d, %m, %y, %H, %M and %S read two digits each, %Y reads four digits and %j reads three digits.
%b requires three characters, and %B requires as many as it needs.
Spaces are treated slightly differently. A space in the string stands for zero or more whitespace characters
in the file. That is, "%H %M" can be used to read "1220" and "12 20" as well as "12 20".
Each set of non-blank characters in the timedata counts as one column in the using n:n specification.
Thus 11:11 25/12/76 21.0 consists of three columns. To avoid confusion, gnuplot requires that you
provide a complete using specification if your file contains timedata.
Since gnuplot cannot read non-numerical text, if the date format includes the day or month in words,
the format string must exclude this text. But it can still be printed with the "%a", "%A", "%b", or
"%B" specifier: see set format (p. 100) for more details about these and other options for printing
timedata. (gnuplot will determine the proper month and weekday from the numerical values.)
See also set xdata (p. 140) and Time/date (p. 39) for more information.
Example:
set timefmt "%d/%m/%Y\t%H:%M"
tells gnuplot to read date and time separated by tab. (But look closely at your data — what began as
a tab may have been converted to spaces somewhere along the line; the format string must match what
is actually in the file.) See also
time data demo.