Yesterday I purchased a Galaxy Note 3. On the calendar app there is an option for one alarm for each event. Are there any android calendar apps that allow 2 alarms for an event?
For the same time and date? Combine the two sounds you want in a sound editor (like Audacity) and use that as the alert.
Unless you want or need another calendar on your device, why not just create two (or more) events for the same date/time with different reminder times. It's easy to do and it does the job.
