Surfer does not support alphanumeric or date/time data. All data to be gridded in Surfer must be numeric. You can work around this by converting your data to Julian dates, plotting the Julian dates, then labeling the axis with the actual date/time data.

Convert your date/time data to Julian dates

The first step is to simply convert the dates/times to Julian dates. Julian dates are a system of time measurement for scientific use. You can do the conversion easily in Excel:

1. Open your data file in Excel.
2. Select your date/time column and choose to format the cells as Number. That will convert the dates/times to Julian dates. You may want to increase the Decimal places if you have time data in addition to dates. For example, see attached XYZ data.xls.
3. Save and close the data file.
4. You can now grid this data file in Surfer and create a map from the data. Now your axes will show the Julian date labels.

Label the axes with the actual date/time data

If you created a non-3D map (contour, image, shaded relief, etc) you can replace the axis labels with the actual date/times by following these steps:

1.     Select the Bottom Axis in the Object Manager for the map (or whatever axis shows the Julian date values).

2.     In the Property Manager, on the General tab uncheck the Show checkbox.

3.     On the Ticks tab set the Major Ticks and Minor Ticks styles both to None.

4.     Now you can either use the Draw | Text option to draw in the date labels, or you can use a post map to plot dates along the X axis as data point labels.

5.     To use a post map, select the Map in the Object Manager, and in the Property Manager, on the Limits tab, note the Y minimum value for the map.

6.     Open the Surfer worksheet, or an Excel worksheet, and create a data file with 3 columns of data for all the tick marks and labels you would like to see on the axis:

a.             X (Julian dates/times)

b.             Y (minimum Y value of map), this will all be the same Y value for all points

c.             label (regular dates, ie. 5/15/05) corresponding to the Julian dates on the same row

For example, see attached Date Labels.xls.

7.     Select the map and go to Map | Add | Post Layer, select the data file and click Open. If you are asked if you want to adjust the map limits, click No.

8.     Select the post map and in the Property Manager, make sure the post map uses the first two columns of data for the X and Y columns and uses the "+" symbol.

9.     Go to the Labels tab and set the label column to be the column containing the label data, and choose to position the labels below the symbol. 

10.  If you want to make adjustments to the date labels, select the post map, and in the Property Manager go to the Labels tab, and make font adjustments or placement changes here.

For an example of the final output, please see attached Date Time axis.srf.

See also: How can I label the axes on my map with dates?