Scheduling recurring jobs

How to make and restart the daemons that perform jobs on a schedule:

Example:

sudo launchctl load /Library/LaunchDaemons/<daemon name>.plist

That is

sudo launchctl load /Library/LaunchDaemons/data1_update.plist

sudo launchctl load /Library/LaunchDaemons/data2_update.plist

sudo launchctl load /Library/LaunchDaemons/data3_update.plist

An example file that updates the file permissions of a drive every 3600 seconds (that is, runs /bin/chmod -R 775 /Volumes/DataDrive/Data1) is: data1_update.plist

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<dict>

<key>Label</key>

<string>com.apple.kfc-data1.plist</string>

<key>ProgramArguments</key>

<array>

<string>/bin/chmod</string>

<string>/Volumes/DataDrive1/Data1</string>

</array>

<key>StartInterval</key>

</dict>

</plist>