Remembering numbers and dates is a complex and highly specific skill.
Lev explains Edit
Many of our students love to read historical material. Almost any field of knowledge has its own history. History comprises of historical processes, heroic leaders, some interesting statistics, and lots of names, dates and numbers.
When you talk about remembering dates, it really requires disambiguation. Do you mean historical events, friends and their birthdays, calendar appointments or something else altogether? There are specific techniques for remembering each type of information. If you need to remember long chains of numbers, there is a very specific method that is briefly presented in Lecture 27. There is a very long list of other methods, see e.g. http://www.mindtools.com/pages/article/newTIM_13.htm.
There was an interesting article regarding memorization of numbers:memorize long numbers with a song. In our course we made an emphasis on chunking methods since they are very fast to learn and use. However, you may find other methods more fun. Try them out.
Markers for numbers are either very generic or very personal. For generic numbers, there are mnemonic number systems. The oldest and simplest is probably http://en.wikipedia.org/wiki/Mnemonic_major_system. A very different generic system is described athttp://www.buildyourmemory.com/numbers.php.
Personally I do not like generic systems, since they look as too much work. An alternative is assigning meaning to numbers based on your own experience. For example 29 Feb is a very special day [happens every 4 years including 2004] and 29 Jan is just a month before. There was 29th of Feb in 2000 and the next after it was in 2004. It is easier to create markers if you add some semantic information, like what happened at 29Jan 2004: for example exploding whale in Taiwanhttp://en.wikipedia.org/wiki/January_2004. Then you get “a whale exploded on a second leap year of this millennium, one month before the leap”. I find little research in Wikipedia both fun and helping…