Merge Weekly Time Intervals

You are given a list of time intervals within a single week. Each time is written as a day-of-week plus a 24-hour clock, for example `Sat 13:00` or `Mon 09:30`. Each interval has the form `[start, end]`, where `start` and `end` are timestamps in the same weekly timeline, and `start <= end`. Write a function that merges all overlapping intervals and returns the merged result in chronological order. Example input: - `[Mon 09:00, Mon 11:00]` - `[Mon 10:30, Mon 12:00]` - `[Sat 13:00, Sat 14:00]` - `[Sat 13:30, Sat 15:00]` Example output: - `[Mon 09:00, Mon 12:00]` - `[Sat 13:00, Sat 15:00]` You should explain how to parse the weekday/time format into a comparable numeric value, then apply interval merging efficiently.