You need to provide a correct cron expression to the recurring job which will fire your desired code.
For example, this cron expression runs the job every hour from 8AM to 8PM.
0 0 8-16 ? * * *Cron is a "whitelist" approach (i.e. when to work) than "blacklist" approach as in your questions (when not to work). Hangfire runs recurring jobs based on cron expressions.