Problem: Graticule axis labels show incorrect interval value
After creating a graticule using the Grids and Graticules wizard, with a fairly small interval (for example, 10'), the axis labels incorrectly show a value of 60'.
Solution or Workaround
Adjust your graticule's point of origin to be close to the location where your incorrect axis label is occurring. Also, re-enter the interval if your interval involves a repeating decimal value.
Right-click the data frame in the layout or in the Table of Contents and select Properties.
Switch to the Grids tab, select the graticule, and click Properties.
Switch to the Intervals tab, and type in values for the X and Y origin that are close to the values in the incorrect label. For example, if your axis label shows a value of 117°60'00"W longitude, enter an X-origin value of -117.
For your X and Y intervals, check if the value is a repeating decimal. For example, an interval of 10' would be listed as 0.166667. Extend this value to a greater number of decimal places, such as 0.16666666.