If your Trigger data includes the day of the week in any of the fields, you can have your Zap only Trigger on certain days. For example, here is how Gmail passes along the date and time:
Since days of the week are present, they can be used in the filter. If a Zap were being set up to only Trigger on Fridays, the filter would look like this:
The "contains" condition is used because there will be other date/timestamp information coming from the field, The "exactly matches" condition would prevent the data from passing the filter conditions in this scenario.
To have your Zap only trigger on weekdays, the filters would look like this:
"AND" are used because both filters need to be true in order for the Zap to not Trigger on weekends. Using an "OR" filter would trigger the Zap all 7 days of the week because one filter condition would always be true, and therefore allow the Zap to continue to the next step.