If you want to leverage the automated highlighting of the Weekly format but have found that you’re combining different periods or parts of your course in a single week or making them straddle two weeks the Periods Format might be what you’re looking for. According to the description,
This course format allows to set duration for each section (period) in days, weeks, months or years. Each individual section (period) may override this duration.
The course settings allow automatically collapse or hide past or future periods. For the past periods it is possible to hide them from course view page but have each individual module still accessible through reports and/or gradebook.
Current section is automatically highlighted.
The format is maintained by Marina Glancy of Moodle HQ and available only for 2.8: https://moodle.org/plugins/view.php?plugin=format_periods