Get notified in app extension server when automatic discount's status turns to ACTIVE from SCHEDULED

When merchants create automatic discounts for a future time, discounts status is assigned as “SCHEDULED”. When the actual time comes, ‘SCHEDULED’ discount status is changed to “ACTIVE”. How can the app server get notified that a change of status is takes place in shopify database. I tried by subscribing to DISCOUNTS/UPDATE webhook. But webhooks sends POST request to webhook handle url of app server only when merchants changes discounts in the shopify backend. Need to get notified when discount status being changed automatically in shopify database.