A nice option could be to run a workflow only in weekdays (monday to friday).
This is useful to avoid end users using custom mode (quite technical for them).
Finally, adding an option for running cron in a different timezone would be really helpful to send emails when day starts there.
I had this use case come up when n8n.cloud was in early access - we wanted to invite people Mon-Thurs so that there was less chance of deployment related support tickets on the weekend. I used the Cron node and set the “mode” to custom. An input field is then available to enter a cron expression.
No expert in cron syntax but there are plenty of free sites that can generate cron expressions via a visual UI - would simply google “Cron expression generator”.
Regarding time zones, each workflow can override the instance’s default time zone. To do this, open a workflow then in left menu: Workflow> Settings> Timezone. Hope that helps!
One of the generators @maxT is referring to is: https://crontab.guru
If you for example want to run something every weekday at 14:00 it would be:
0 14 * * 1,2,3,4,5
Thanks Jan.
I usually apply custom crons 
My mention was only for non techie end-users.
By the way, those cron generators don’t generate seconds in format and perhaps this could be a bit confusing when pasting auto-generated cron formats.
Thanks!
Ah makes sense
The seconds are actually optional. So you can use it with or without.