Introduce year instead of whole date in date type field using ArcGIS Desktop?

Question

I have a field with numbers in it (concentration of chemical compounds that were presented in aquatic environments) and I'd like to combine them with a field which would have date type capabilities but as a unique year (e.g. 2013, 2008 etc.) instead of a whole date (2/5/2013, 5/8/2008 etc.).

The year data represent the years of chemical analysis of water samples.

The general concept of this work is to provide me finally the information of the concentration and the year of analysis of a certain compound.

Also I'd like to have the ability to select concentrations by year.

For example: before the year of 2004 what was the concentrations of these substances?

How can I achieve the above?

Answer 1

You could just use a an integer (called year). That will do what you need. And your query in the example you give would be SELECT * from some_table WHERE year < 2004

Answer 2

The ArcGIS tool "Calculate field" can be used for that.

Set expression to

(datetime.datetime.strptime( !fulldate! , "%m/%d/%Y")).year

and the code block to

import datetime

the parser to python and the input and output fields as you like.

I recommend crerating a "year" output field and retaining the original date (which was in the fulldate column in my example).