diff --git a/btrfs-snapshots.sh b/btrfs-snapshots.sh
index 456c16d..65586d2 100755
--- a/btrfs-snapshots.sh
+++ b/btrfs-snapshots.sh
@@ -6,7 +6,7 @@ TMP_MNT=${TMP_MNT:-/var/tmp/btrfs-backup}
 vols=()
 del=
 dryrun=0
-periodity=${a%/*}
+periodity=${0%/*}
 periodity=${periodity##*/}
 if [[ $periodity =~ ^cron\... ]]; then
     periodity=${periodity#cron}
diff --git a/install.sh b/install.sh
new file mode 100755
index 0000000..51fb569
--- /dev/null
+++ b/install.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+for f in hourly daily weekly monthly; do
+    sudo cp btrfs-snapshots.sh /etc/cron.$f/btrfs-snapshots;
+done