System Scheduler - System Scheduler for Windows, Free Task Scheduler Software replace Microsoft Windows Task Scheduler
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
VisualCron - VisualCron is an automation, integration and task scheduling tool for Windows.
Gnome Clocks - Clock application designed for GNOME 3
Freebyte Task Scheduler - Freebyte Task Scheduler, freeware for Windows and Linux/Wine.
AlarmDJ - Online Alarm Clock - Use YouTube videos or MP3 files as alarm sound. Works offline.