awesome, thanks for your share,
This addon works with php and jquery, not python. So it cannot be used as a custom component.
For those coming here when searching a good but simple scheduler, this one is very nice https://github.com/nielsfaber/scheduler-card
I am unable to install either https://github.com/nielsfaber/scheduler-component or https://github.com/nielsfaber/scheduler-card through
Supervisor > Add-on store > Repositories > Add/Close > Reload
The add-ons never show up and I have these errors in the logs :
20-10-03 17:55:28 INFO (MainThread) [supervisor.store.git] Clone add-on https://github.com/nielsfaber/scheduler-component repository
20-10-03 17:55:30 ERROR (MainThread) [supervisor.utils.json] Can't read json from /data/addons/git/a15769b9/repository.json: [Errno 2] No such file or directory: '/data/addons/git/a15769b9/repository.json'
20-10-03 17:55:30 WARNING (MainThread) [supervisor.store.data] Can't read repository information from /data/addons/git/a15769b9/repository.json
20-10-03 17:55:30 ERROR (MainThread) [supervisor.utils.json] Can't read json from /data/addons/git/b38affab/repository.json: [Errno 2] No such file or directory: '/data/addons/git/b38affab/repository.json'
20-10-03 17:55:30 WARNING (MainThread) [supervisor.store.data] Can't read repository information from /data/addons/git/b38affab/repository.json
20-10-03 17:55:30 INFO (MainThread) [supervisor.store] Load add-ons from store: 71 all - 0 new - 0 remove
20-10-03 17:55:37 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/nielsfaber/scheduler-card repository
20-10-03 17:55:37 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/vkorn/hassio-addons repository
20-10-03 17:55:37 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/nielsfaber/scheduler-component repository
20-10-03 17:55:37 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/home-assistant/hassio-addons repository
20-10-03 17:55:37 INFO (MainThread) [supervisor.store.git] Update add-on https://github.com/hassio-addons/repository repository
What am I missing please ? 
Because that’s not where you install it from. That area is for installing addons & custom addons. You’re trying to install a custom integration and a custom card. This is done through HACS which is a custom integration as well.
An addon is a ‘package’ that runs along side of Home Assistant.
An integration is a ‘package’ that is installed inside Home Assistant.
Sometimes, when you install an addon, you might need to install an integration to get home assistant to talk to the addon. Otherwise the addons are 100% separate from home assistant.
Thanks, works fine! Was looking for something like this for a long time!