• fix parsing %p to reinterpret the hour on a 12-hour clock
• fix parsing %s to validate the range of Unix time
• fix parsing %s in a location or with %z to keep the absolute time
• fix parsing %G and %g without %V to start at the first week of the ISO year
• fix parsing %G and %g to return error with non-ISO date directives
• fix parsing week date directives (%V, %U, %W) with leap second
• fix parsing time zone name of %Z following %z
• fix parsing %Z for numeric and mixed case time zone abbreviations (+07, ChST)
• fix parsing %Z not to retain the source string in the time zone name
• fix %^Z and %#Z mangling digits and symbols in time zone name
• fix %#Z panicking on a single-character time zone name
• fix error messages of non-ASCII format directives and characters
• improve performance of parsing by avoiding defer (10-28% less time in benchmarks)
• improve performance of parsing a byte slice converted to a string (no allocation up to 32 bytes)
• improve performance of formatting by emitting digits at once (2-6% less time in benchmarks)