diff --git a/app/graphql/schema.graphql b/app/graphql/schema.graphql
index c52aa19a..6767bb08 100644
--- a/app/graphql/schema.graphql
+++ b/app/graphql/schema.graphql
@@ -1,7 +1,9 @@
 type Assignment {
   createdAt: ISO8601DateTime!
+  endsOn: ISO8601Date
   id: ID!
   project: Project!
+  startsOn: ISO8601Date
   status: String!
   updatedAt: ISO8601DateTime!
   user: User!
@@ -28,6 +30,11 @@ type Company {
   users: [User!]!
 }
 
+"""
+An ISO 8601-encoded date
+"""
+scalar ISO8601Date @specifiedBy(url: "https://tools.ietf.org/html/rfc3339")
+
 """
 An ISO 8601-encoded datetime
 """
diff --git a/app/graphql/types/staff_plan/assignment_type.rb b/app/graphql/types/staff_plan/assignment_type.rb
index cdc0ec44..cc660a3e 100644
--- a/app/graphql/types/staff_plan/assignment_type.rb
+++ b/app/graphql/types/staff_plan/assignment_type.rb
@@ -7,6 +7,8 @@ class AssignmentType < Types::BaseObject
       field :user, Types::StaffPlan::UserType, null: false
       field :project, Types::StaffPlan::ProjectType, null: false
       field :status, String, null: false
+      field :starts_on, GraphQL::Types::ISO8601Date, null: true
+      field :ends_on, GraphQL::Types::ISO8601Date, null: true
       field :created_at, GraphQL::Types::ISO8601DateTime, null: false
       field :updated_at, GraphQL::Types::ISO8601DateTime, null: false