When an item’s date changes, adjust subitem's timeline by the same offset

video1.0<iframe src="https://www.loom.com/embed/40bf7635107d43a2af18fbe7f26affe9" frameborder="0" width="1280" height="960" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>9601280Loomhttps://www.loom.com9601280https://cdn.loom.com/sessions/thumbnails/40bf7635107d43a2af18fbe7f26affe9-beb1dc24c11e9990.gif302.593When an item’s date changes, adjust subitem's timeline by the same offset