Can I set Philips device's alarm for certain days only?

Yes. There are 3 choices of setting the alarm for certain days of the week: 1. Setting the alarm for weekdays (Monday to Friday); 2. Setting the alarm for weekends (Saturday and Sunday); 3. Setting the alarm for all days of the week. However, the device does not accommodate the setting of alarm for one particular day of the week. You may need to set the alarm manually in this particular circumstance. Refer to the user manual for the method of setting the alarm for your model. Note: For the settings to function correctly, make sure the date (that is year, month and day) is set correctly.