eLuach Your personal hebrew calendar service. Use it to find times of shabbat and festivals, sidrah of the week, dates of festivals and fasts, yahrzeits, barmitzvahs, hebrew birthdays, daf yomi and more.
Register You don't have to register, this is all free!! However if you register then you will be able to save your favourite cities, yahrzeit and anniversary dates. So it might be useful to you.
Help with Microsoft Outlook Many people ask me for help in getting Jewish Calendar items into Outlook. Click here for some help on this.
Add-in for Microsoft Excel I have written an add-in which can be used in Excel to calculate Jewish calendar items. To download it right-clicking here. It is free and provided "as-is", without any documentation. You will need to be fairly experienced with Excel to use it.

There is also a sample spreadsheet which you can use with this add-in. Right-click here for the sample spreadsheet.