This Behaviour helps to view time/date/timestamp/datetime from db to local Date / Time / Date Time format and in local Timezone. And save into db in with db timezone and db format. You only need to include this behaviour in models where need this facility.
You have that, when a product is on development they can change its API anytime. This change is quite important though, its related on how to set the events of your form, for example, the useful beforeSubmit.