diff --git a/src/app.rs b/src/app.rs
index 318a3e0..6e831f5 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -27,12 +27,17 @@ pub(crate) enum Mode {
     },
     /// The timer mode displays the remaining time until the timer is finished.
     Timer {
+        /// Initial duration for timer, value can be 10s for 10 seconds, 1m for 1 minute, etc.
         #[clap(short, long, value_parser = parse_duration, default_value = "5m")]
         duration: Duration,
 
         /// Hide milliseconds
         #[clap(long = "no-millis", short = 'M', takes_value = false)]
         no_millis: bool,
+
+        /// Command to run when the timer ends
+        #[clap(long, short, multiple = true, allow_hyphen_values = true)]
+        execute: Vec<String>,
     },
     /// The stopwatch mode displays the elapsed time since it was started.
     Stopwatch,
@@ -79,13 +84,20 @@ impl App {
             Mode::Timer {
                 duration,
                 no_millis,
+                execute,
             } => {
                 let format = if *no_millis {
                     DurationFormat::HourMinSec
                 } else {
                     DurationFormat::HourMinSecDeci
                 };
-                self.timer = Some(Timer::new(duration.to_owned(), self.size, style, format));
+                self.timer = Some(Timer::new(
+                    duration.to_owned(),
+                    self.size,
+                    style,
+                    format,
+                    execute.to_owned(),
+                ));
             }
             Mode::Stopwatch => {
                 self.stopwatch = Some(Stopwatch::new(self.size, style));
diff --git a/src/app/modes/timer.rs b/src/app/modes/timer.rs
index 6865e6e..29c9cdb 100644
--- a/src/app/modes/timer.rs
+++ b/src/app/modes/timer.rs
@@ -1,3 +1,5 @@
+use std::{cell::RefCell, process::Command};
+
 use chrono::{DateTime, Duration, Local};
 use clock_tui::bricks_text::BricksText;
 use tui::{buffer::Buffer, layout::Rect, style::Style, widgets::Widget};
@@ -7,19 +9,29 @@ use super::{format_duration, render_centered, DurationFormat};
 pub struct Timer {
     pub size: u16,
     pub style: Style,
+    pub execute: Vec<String>,
     format: DurationFormat,
     duration: Duration,
     ended_at: Option<DateTime<Local>>,
+    execute_result: RefCell<Option<String>>,
 }
 
 impl Timer {
-    pub(crate) fn new(duration: Duration, size: u16, style: Style, format: DurationFormat) -> Self {
+    pub(crate) fn new(
+        duration: Duration,
+        size: u16,
+        style: Style,
+        format: DurationFormat,
+        execute: Vec<String>,
+    ) -> Self {
         Self {
             duration,
             size,
+            execute,
             style,
             format,
             ended_at: Some(Local::now() + duration),
+            execute_result: RefCell::new(None),
         }
     }
 
@@ -33,8 +45,8 @@ impl Timer {
                 self.duration = Duration::zero();
             } else {
                 self.duration = end_at - Local::now();
+                self.ended_at = None;
             }
-            self.ended_at = None;
         }
     }
 
@@ -54,10 +66,34 @@ impl Timer {
     }
 }
 
+fn execute(execute: &Vec<String>) -> String {
+    let mut cmd = Command::new("sh");
+    cmd.arg("-c");
+    let cmd_str = execute.join(" ");
+    cmd.arg(cmd_str);
+    let output = cmd.output();
+    match output {
+        Ok(output) => {
+            if !output.status.success() {
+                format!("[ERROR] {}", String::from_utf8_lossy(&output.stderr))
+            } else {
+                format!("[SUCCEED] {}", String::from_utf8_lossy(&output.stdout))
+            }
+        }
+        Err(e) => {
+            format!("[FAILED] {}", e)
+        }
+    }
+}
+
 impl Widget for &Timer {
     fn render(self, area: Rect, buf: &mut Buffer) {
         let remaining_time = self.remaining_time();
         let time_str = if remaining_time < Duration::zero() {
+            if self.execute.len() > 0 && self.execute_result.borrow().is_none() {
+                let result = execute(&self.execute);
+                *self.execute_result.borrow_mut() = Some(result);
+            }
             if remaining_time.num_seconds() % 2 == 0 {
                 return;
             } else {
@@ -71,7 +107,7 @@ impl Widget for &Timer {
         let footer = if self.is_paused() {
             Some("PAUSED (press <SPACE> to resume)".to_string())
         } else {
-            None
+            self.execute_result.borrow().clone()
         };
         render_centered(area, buf, &text, None, footer);
     }