v2.4.0

• Allow writing worksheets without a block using add_worksheet (#42, #45)
• Deprecate calling add_worksheet with a block, use write_worksheet instead (#45)
• Relax rubyzip development dependency to allow current version (#46)

v2.3.0

• Speed up date / time conversion to OA format (#39)

v2.2.0

• Allow usage with zip_tricks 5.x gem (#38)

v2.1.0

• New :columns option, allowing column widths to be specified (#25)
• Fix compatibility with ruby --enable-frozen-string-literal (#27)
• Support giving the worksheet name as an option to write_worksheet (#28)

v2.0.1

• Rescue gracefully from invalid dates with auto-format (#22)
• Remove unused ZipTricksFibers IO wrapper (#24)

v2.0.0

• Replace RubyZip with ZipTricks as default compressor (#16)
• Drop support for Ruby < 2.1.0 (required for zip_tricks gem)
• Deprecate :io_wrapper option, you can now pass wrapper instances (#20)

v1.3.2

• Fix circular require in workbook
• Fix wrong escaping of extended Unicode characters

v1.3.1

• Restore stringio require in workbook

v1.3.0

• Drop rubyzip buffering workarounds, require rubyzip >= 1.2.0 (#17)
• Drop Ruby 1.9.1 compatibility (rubyzip 1.2 requires ruby >= 1.9.2)
• Refactor IO wrappers (#18)

v1.2.0

• Add support for customizing default font (#17)