Calculations online dating
This type of calculation is not supported on the spatial field from the calculation interface in You may want to add time to or subtract time from a date field or date literal value to produce an updated date field.
For example, you can calculate a future inspection or review date by adding time to a date.
One of the most common calculations you perform is to derive a new numeric value based on existing values in your feature layer.
For example, you might subtract one year's sales totals for all your stores from sales totals from another year to find the change in profit from one year to the next, or you might divide the total number of residents under 18 years of age by the total population to determine the fraction of the population that is under 18.
You could use either of the following calculations to produce an inspection date one month (30 days) after this installation date.
The number result (in days) can be a whole number and can also include a fraction—for example, 1.5 would represent one and a half days, or 36 hours.
In the electric meter inspection example mentioned above, any of the following calculations can be used to calculate the length of time between an installation date of 6/1/2015 and an inspection date of 10/1/2015.
If it is, you can then calculate the original field to equal the added field.
Once you confirm the values are correct in the original field, you can delete the field you added.