core/homeassistant/components/channels/services.yaml

seek_forward:
  description: Seek forward by a set number of seconds.
  fields:
    entity_id:
      description: Name of entity for the instance of Channels to seek in.
      example: "media_player.family_room_channels"

seek_backward:
  description: Seek backward by a set number of seconds.
  fields:
    entity_id:
      description: Name of entity for the instance of Channels to seek in.
      example: "media_player.family_room_channels"

seek_by:
  description: Seek by an inputted number of seconds.
  fields:
    entity_id:
      description: Name of entity for the instance of Channels to seek in.
      example: "media_player.family_room_channels"
    seconds:
      description: Number of seconds to seek by. Negative numbers seek backwards.
      example: 120