diff --git a/src/main.rs b/src/main.rs
index 4b1f3ec..0bb897d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,6 +13,10 @@ struct Args {
     #[clap(value_parser)]
     class: String,
 
+    /// The semester you want (useful only in 3rd year)
+    #[clap(short, long, value_parser)]
+    semester: Option<i8>,
+
     /// Export to iCalendar format (.ics)
     #[clap(short, long, action = ArgAction::SetTrue, default_value_t = false)]
     export: bool,
@@ -42,7 +46,7 @@ async fn main() {
         year,
         letter.unwrap_or_default()
     );
-    let timetable = timetable::timetable(year, 1, letter).await;
+    let timetable = timetable::timetable(year, args.semester, letter).await;
 
     println!("Fetch informations about the year...");
     let info = info::info().await;
diff --git a/src/timetable.rs b/src/timetable.rs
index 036d9da..e79c96a 100644
--- a/src/timetable.rs
+++ b/src/timetable.rs
@@ -7,9 +7,11 @@ pub mod models;
 /// Fetch the timetable for a class
 pub async fn timetable(
     year: i8,
-    semester: i8,
+    semester_opt: Option<i8>,
     letter: Option<char>,
 ) -> (Vec<String>, (usize, Vec<models::Day>)) {
+    let semester = get_semester(semester_opt, letter);
+
     let document = get_webpage(year, semester, letter)
         .await
         .expect("Can't reach timetable website.");
@@ -123,7 +125,7 @@ async fn get_webpage(
                     2 => ['x', 'y', 'z'],
                     _ => panic!("{}", panic_semester_message),
                 };
-                let c = letter.expect(panic_letter_message);
+                let c = letter.expect(panic_letter_message).to_ascii_lowercase();
                 if allow_letters.contains(&c) {
                     format!("{}/l1-{}.html", base_url, c)
                 } else {
@@ -136,7 +138,7 @@ async fn get_webpage(
                     2 => ['x', 'y'],
                     _ => panic!("{}", panic_semester_message),
                 };
-                let c = letter.expect(panic_letter_message);
+                let c = letter.expect(panic_letter_message).to_ascii_lowercase();
                 if allow_letters.contains(&c) {
                     format!("{}/l2-{}.html", base_url, c)
                 } else {
@@ -279,3 +281,9 @@ pub fn build(timetable: T, dates: D) -> Vec<models::Course> {
 
     semester
 }
+
+/// Get the current semester depending on the letter or the current date
+fn get_semester(_semester: Option<i8>, _letter: Option<char>) -> i8 {
+    // TODO
+    1
+}