diff --git a/src/lib.rs b/src/lib.rs
index 28d17f2..1fb70d5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,6 +8,7 @@ mod marks;
 mod payments;
 mod stdtype;
 mod subjects;
+mod substitutions;
 mod themes;
 mod user;
 
@@ -18,8 +19,9 @@ pub use error::Error;
 pub use events::Events;
 pub use homework::{Homework, HomeworkListItem};
 pub use marks::{Mark, Marks, SubjectMarks};
-pub use payments::{ClassfundPayments, ClassfundSummary, Payment, PaymentMonthlyData, AddBalance};
+pub use payments::{AddBalance, ClassfundPayments, ClassfundSummary, Payment, PaymentMonthlyData};
 pub use stdtype::StdType;
 pub use subjects::{Subject, Subjects};
+pub use substitutions::{SubstitutionChange, Substitutions};
 pub use themes::{Theme, Themes};
 pub use user::{Module, User};
diff --git a/src/substitutions.rs b/src/substitutions.rs
new file mode 100644
index 0000000..088c70e
--- /dev/null
+++ b/src/substitutions.rs
@@ -0,0 +1,23 @@
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "PascalCase")]
+pub struct Substitutions {
+    pub from: DateTime<Utc>,
+    pub to: DateTime<Utc>,
+    pub changes: Vec<SubstitutionChange>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "PascalCase")]
+pub struct SubstitutionChange {
+    pub change_subject: Option<String>, //Unknown if string is the right type
+    pub day: DateTime<Utc>,
+    pub hours: String,
+    pub change_type: String,
+    pub description: String,
+    pub time: String,
+    pub type_abbrev: Option<String>, //Unknown if string is the right type,
+    pub type_name: Option<String>,   //Unknown if string is the right type
+}
diff --git a/tracker.md b/tracker.md
index 11ab264..8fdecf8 100644
--- a/tracker.md
+++ b/tracker.md
@@ -11,7 +11,7 @@
 - [ ]  measures
 - [x]  payments
 - [x]  subjects
-- [ ]  substitutions
+- [x]  substitutions
 - [x]  themes
 - [ ]  timetable
 - [x]  user