I'm working on a web based tool for creating timelines, something that I've found to be quite helpful when researching a particular topic. The tool is free and (hopefully) very simple to use. Custom dates can be added, but it also allows you to import dates from Wikipedia.
You can give it a go a http://timeline-maker.com
I hope you won't consider this post spammy, I'm not advertising or charging for this product. I just think it's a useful tool that isn't being done well elsewhere.
I'm continually developing the product, and it really helpful to have feedback to guide that. If you'd like something changed leave a message here, or use the feedback form on the website, and I'll get back to you.