Select scale > Editor > Edit > Time
Use to edit the time scale for the x-axis.
Time Scale
Index: Choose to label the x-axis with integers. Type the start value.
Calendar: Choose to label the x-axis with a calendar scale, then choose the calendar units.
Clock: Choose to label the x-axis with a clock scale, then choose the clock units.
Stamp: Choose to label the x-axis with values from one or more stamp columns.
Stamp columns (1-3): Enter up to three columns containing scale values.
Start Values: Type the start value for each component of the time scale.
Data Increment: Uncheck to enter the data interval between values on the innermost time scale.