Welcome to the community!
You can activate and deactivate workflows using n8n API.
This could be an external service e.g. cron job calling endpoints or another workflow on n8n managing your target workflow.
n8n API not accessible to trial users though.
If this addresses your request please mark this post as a Solution.
Do you want to pause the entire workflow so that the webhook doesn’t start the process at all?
Or would you prefer to add a waiting period within the workflow itself?
I would like to pause the entire workflow to don’t consume credit
Here you go.
You need to edit Workflow ID. You will find the required data point in the url of the workflow you want to manage.
I didn’t test it extensively in a real-world scenario. Curious to know if it actually works as intended.
Remember, you need to activate it! This will eat up the quota of active workflows but at least it will cost only two executions a day.
If you want to trigger your target workflow activity outside of n8n, you will need to employ n8n API and some external service to poll it.
If this resolves your question, please mark this post as a 
Solution.
You need an API key (see Authentication | n8n Docs) and use it to create n8n credentials. This is not available to trial users though.
Base URL in credentials needs to be https://YOURn8nAPPNAME.app.n8n.cloud/api/v1. You can use this credential to manage any of your workflows, hence it shouldn’t be bound to any specific workflow.
You put ID of the workflow you want to manage in the Workflow ID node of your copy of workflows scheduler.
When i try to use your path it doesn’t works …
For exemple, my n8n dashboard have this path
https://example.app.n8n.cloud/home/workflows
if i put this path
https://example.app.n8n.cloud/api/v1
If i use this path
https://example.app.n8n.cloud it works …
But same issue in the activation workfow …
Path with /api/v1 in it still works for me. I use n8n cloud v1.83.2 (yet had my n8n creds initially set up like this while on earlier versions). The Base URL hint still suggests using /api/v1 URI. So, it’s strange that it won’t work for you.
The API key, you get it following the instructions here Authentication | n8n Docs :
You need to copy it and then paste it in the credentials configuration.
The issue with credential is solved now with the API key (not clear in the doc)
Thank you
Tested and it works !!!
thank you
Glad it worked out for you.
do not forget to deactivate and then activate this workflow every time you change the schedule, otherwise the system won’t pick up to the changes. This is an expected behaviour.
Also check timezones everywhere (your n8n account, workflow timezone etc) to be matching you needs. Just in case the schedule seems to be off by several hours consistently.
Happy n8ning! 
