Need help to write a groovy script which will update a number field based on the number of times a custom field value changes

[acoddc2]

Hi There,
I am a project manager using JIRA and need to easily track the number of times a custom field we have added to JIRA changes value.

We have a date field which we use to tracked target code complete date.
I want to add a field which will start at 0 and increment each time that date field value changes.

I am not a programmer and need some help writing a groovy script for this.
I assume this can be done with a groovy number field.

Can someone help me out?