Calendar enhancements

• Fixed the calendar for time zones which start after UTC (e.g. USA). Thx @cgauthier!
• Fixed an issue when resorting table headers.

All changes in 1 commit: 70f795e

Demo video: https://youtu.be/Axi55BmeM-w

Online Demo: https://neomjs.com/dist/production/examples/calendar/basic/index.html