diff --git a/core/admin/mailu/internal/templates/default.sieve b/core/admin/mailu/internal/templates/default.sieve
index 5a80a181..d771ee99 100644
--- a/core/admin/mailu/internal/templates/default.sieve
+++ b/core/admin/mailu/internal/templates/default.sieve
@@ -32,9 +32,6 @@ if exists "X-Virus" {
   stop;
 }
 
-{% if user.reply_enabled %}
-if currentdate :value "le" "date" "{{ user.reply_enddate }}"
-{
- vacation :days 1 :subject "{{ user.reply_subject }}" "{{ user.reply_body }}";
-}
+{% if user.reply_active  %}
+vacation :days 1 :subject "{{ user.reply_subject }}" "{{ user.reply_body }}";
 {% endif %}
diff --git a/core/admin/mailu/models.py b/core/admin/mailu/models.py
index 51d07f24..3653011f 100644
--- a/core/admin/mailu/models.py
+++ b/core/admin/mailu/models.py
@@ -250,6 +250,8 @@ class User(Base, Email):
     reply_enabled = db.Column(db.Boolean(), nullable=False, default=False)
     reply_subject = db.Column(db.String(255), nullable=True, default=None)
     reply_body = db.Column(db.Text(), nullable=True, default=None)
+    reply_startdate = db.Column(db.Date, nullable=False,
+        default=date(1900, 1, 1))
     reply_enddate = db.Column(db.Date, nullable=False,
         default=date(2999, 12, 31))
 
@@ -276,6 +278,15 @@ class User(Base, Email):
         else:
             return self.email
 
+    @property
+    def reply_active(self):
+        now = date.today()
+        return (
+            self.reply_enabled and
+            self.reply_startdate < now and
+            self.reply_enddate > now
+        )
+
     scheme_dict = {'PBKDF2': "pbkdf2_sha512",
                    'BLF-CRYPT': "bcrypt",
                    'SHA512-CRYPT': "sha512_crypt",
diff --git a/core/admin/mailu/ui/forms.py b/core/admin/mailu/ui/forms.py
index 326d721b..4f7a30ae 100644
--- a/core/admin/mailu/ui/forms.py
+++ b/core/admin/mailu/ui/forms.py
@@ -117,6 +117,7 @@ class UserReplyForm(flask_wtf.FlaskForm):
     reply_subject = fields.StringField(_('Reply subject'))
     reply_body = fields.StringField(_('Reply body'),
         widget=widgets.TextArea())
+    reply_startdate = fields.html5.DateField(_('Start of vacation'))
     reply_enddate = fields.html5.DateField(_('End of vacation'))
     submit = fields.SubmitField(_('Update'))
 
diff --git a/core/admin/mailu/ui/templates/user/reply.html b/core/admin/mailu/ui/templates/user/reply.html
index 7906bc42..7225a178 100644
--- a/core/admin/mailu/ui/templates/user/reply.html
+++ b/core/admin/mailu/ui/templates/user/reply.html
@@ -13,14 +13,17 @@
 <form class="form" method="post" role="form">
   {{ form.hidden_tag() }}
   {{ macros.form_field(form.reply_enabled,
-      onchange="if(this.checked){$('#reply_subject,#reply_body,#reply_enddate').removeAttr('readonly')}
+      onchange="if(this.checked){$('#reply_subject,#reply_body,#reply_enddate,#reply_startdate').removeAttr('readonly')}
                 else{$('#reply_subject,#reply_body,#reply_enddate').attr('readonly', '')}") }}
   {{ macros.form_field(form.reply_subject,
       **{("rw" if user.reply_enabled else "readonly"): ""}) }}
     {{ macros.form_field(form.reply_body, rows=10,
         **{("rw" if user.reply_enabled else "readonly"): ""}) }}
   {{ macros.form_field(form.reply_enddate,
-      **{("rw" if user.reply_enabled else "readonly"): ""}) }}
+        **{("rw" if user.reply_enabled else "readonly"): ""}) }}
+  {{ macros.form_field(form.reply_startdate,
+        **{("rw" if user.reply_enabled else "readonly"): ""}) }}
+
   {{ macros.form_field(form.submit) }}
 </form>
 {% endcall %}
diff --git a/core/admin/migrations/versions/3b281286c7bd_.py b/core/admin/migrations/versions/3b281286c7bd_.py
new file mode 100644
index 00000000..57b5c327
--- /dev/null
+++ b/core/admin/migrations/versions/3b281286c7bd_.py
@@ -0,0 +1,24 @@
+""" Add a start day for vacations
+
+Revision ID: 3b281286c7bd
+Revises: 25fd6c7bcb4a
+Create Date: 2018-09-27 22:20:08.158553
+
+"""
+
+revision = '3b281286c7bd'
+down_revision = '25fd6c7bcb4a'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    with op.batch_alter_table('user') as batch:
+        batch.add_column(sa.Column('reply_startdate', sa.Date(), nullable=False,
+            server_default="1900-01-01"))
+
+
+def downgrade():
+    with op.batch_alter_table('user') as batch:
+        batch.drop_column('reply_startdate')