Character encoding — how characters map to bytes
This chapter starts from the difference between character set and encoding scheme. It covers four ways of counting characters, normalization for same-looking-different-bytes, collation deciding sort order and comparison, byte-based storage limits, and vulnerabilities from interpretation boundaries being multiple.
Datetimes and time zones — the same instant under different names
This chapter organizes datetime handling into three: instant, local time, and duration. It covers why offsets and time zones are different, how storage differs between past records and future events, that day boundaries move with time zones, that string interpretation changes by form, and pitfalls of calendar arithmetic.