diff --git a/period/cycles.py b/period/cycles.py
index e918863..c6cc0f1 100644
--- a/period/cycles.py
+++ b/period/cycles.py
@@ -1,4 +1,5 @@
 from itertools import cycle
+from time import get_clock_info
 from tracemalloc import start
 from flask import (
     Blueprint, flash, g, redirect, render_template, request, url_for
@@ -23,11 +24,13 @@ def index():
 @bp.route('/create', methods=('GET', 'POST'))
 def create():
     if request.method == 'POST':
-        start_time = pendulum.from_format(request.form['start_time'], 'YYYY-MM-DD')
-        # start_time = start_time.to_datetime_string()
+        start_time_stamp = request.form['start_time']
+        start_time = pendulum.from_format(start_time_stamp, 'YYYY-MM-DD')
         try:
+            end_time_stamp = request.form['end_time']
             end_time = pendulum.from_format(request.form['end_time'], 'YYYY-MM-DD')
         except ValueError:
+            end_time_stamp = "1900-01-01"
             end_time = pendulum.datetime(1900,1,1)
         error = None
         print(request.form['end_time'])
@@ -47,13 +50,72 @@ def create():
             if end_time > start_time:
                 db.execute(
                     'INSERT INTO cycle (start_time, end_time, cycle_length) VALUES (?, ?, ?)',
-                    (start_time.to_datetime_string(), end_time.to_datetime_string(), cycle_length)
+                    (start_time_stamp, end_time_stamp, cycle_length)
                 )
             else:
                 db.execute(
                     'INSERT INTO cycle (start_time, cycle_length) VALUES (?, ?)',
-                    (start_time.to_datetime_string(), cycle_length)
+                    (start_time_stamp, cycle_length)
                 )
             db.commit()
             return redirect(url_for('index'))
-    return render_template('cycle/create.html')
\ No newline at end of file
+    return render_template('cycle/create.html')
+
+def get_cycle(id):
+    cycle = get_db().execute(
+        'SELECT * from cycle WHERE id = ?',
+        (id,)
+    ).fetchone()
+
+    if cycle is None:
+        abort(404, f"Cycle id {id} doesn't exist.")
+
+    return cycle
+
+@bp.route('/<int:id>/update', methods=('GET', 'POST'))
+def update(id):
+    cycle = get_cycle(id)
+    print(cycle['end_time'])
+
+    if request.method == 'POST':
+        start_time_stamp = request.form['start_time']
+        start_time = pendulum.from_format(start_time_stamp, 'YYYY-MM-DD')
+        try:
+            end_time_stamp = request.form['end_time']
+            end_time = pendulum.from_format(end_time_stamp, 'YYYY-MM-DD')
+            print(end_time)
+        except ValueError:
+            end_time_stamp = "1900-01-01"
+            end_time = pendulum.datetime(1900,1,1)
+        error = None
+        if end_time is None:
+            end_time = "2999-01-01"
+        print(end_time)
+
+        if not start_time:
+                error = "You must provide a start date"
+
+        if end_time > start_time:
+                cycle_length = (end_time - start_time).days
+        else:
+            cycle_length = (pendulum.now() - start_time).days
+
+        if error is not None:
+            flash(error)
+        else:
+            db = get_db()
+            if end_time > start_time:
+                db.execute(
+                    'UPDATE cycle SET start_time = ?, end_time = ?, cycle_length = ?'
+                    ' WHERE id = ?',
+                    (start_time.to_datetime_string(), end_time.to_datetime_string(), cycle_length, id)
+                )
+            else:
+                db.execute(
+                    'UPDATE cycle SET start_time = ?, cycle_length = ?'
+                    ' WHERE id = ?',
+                    (start_time.to_datetime_string(), cycle_length, id)
+                )
+            db.commit()
+            return redirect(url_for('index'))
+    return render_template('cycle/update.html', cycle=cycle)
\ No newline at end of file
diff --git a/period/templates/cycle/index.html b/period/templates/cycle/index.html
index 8ae4fb1..972a5ab 100644
--- a/period/templates/cycle/index.html
+++ b/period/templates/cycle/index.html
@@ -10,6 +10,7 @@
       <header>
         <div>
           <h1>{{ cycle['id'] }}</h1>
+          <a class="action" href="{{ url_for('cycles.update', id=cycle['id'])}}">Edit</a>
           <div class="about">Started: {{ cycle['start_time'] }} and ended: {{ cycle['end_time'] }}</div>
         </div>
       </header>
diff --git a/period/templates/cycle/update.html b/period/templates/cycle/update.html
new file mode 100644
index 0000000..a3f8234
--- /dev/null
+++ b/period/templates/cycle/update.html
@@ -0,0 +1,15 @@
+{% extends 'base.html' %}
+
+{% block header %}
+  <h1>{% block title %}Edit Cycle{% endblock %}</h1>
+{% endblock %}
+
+{% block content %}
+  <form method="post">
+    <label for="start_time">Start Time</label>
+    <input name="start_time" id="title" value="{{ request.form['start_time'] or cycle['start_time'][:10] }}" required type="date">
+    <label for="end_time">End Time</label>
+    <input name="end_time" id="end_time" value="{{ request.form['end_time'] or cycle['end_time'][:10] if cycle['end_time'] is not none }}" type="date">
+    <input type="submit" value="Save">
+  </form>
+{% endblock %}
\ No newline at end of file