DCL:GRPH2:UCPACK : Coordinate Axis Routines for Date
The UCPACK is a subroutine package for plotting a coordinate axis with dates for tick marks.
This package is written based on the subroutine packages UXPACK/UYPACK/UZPACK (See Chapter 3) for plotting Cartesian coordinate systems.
To plot this type of coordinate axis, the normalization transformation must be set using units in days. The coordinate axis will be plotted from the position corresponding to 0 in the user-defined coordinate system (UC). Therefore, if you wish to allot a period from Jan. 1 to Jan. 31 to the full viewport size, specify the ends of the window as (0, 30).
Below are explanation of the arguments cside, jd0, and nd, which are common in the subroutines.