Wolfram|Alpha can do date-time conversions, for example to convert between Auckland and Rio de Janerio for today
or to convert for a specific day
Add multiple places to compare times anywhere in the world.
Click on a row, to adjust time for that place.
Greenwich Mean Time - Time Zone Converter
Your choice of places are saved to browser (no need for registration).
Yes! I actually just posted about this - IATA has released an interactive map that shows you the countries, restrictions, etc, based on Timatic data, as Frank has said in his answer.
However, you can also look at Travelbans.org, which is another site you can use which gives you continuously updated information on travel restrictions for every country.