# Count On

## Explorer

#### Even Today is Unusual!

2^{nd} February 2000 is an unusual date. Why? Because 2/2/2000 is made up of
**only even digits**.

An **even number** is one that is a multiple of 2 and
just needs to end with an even digit, e.g. 1998. However, today
we are interested in **all the digits being even**. (Is 0 even? Yes, in as much as the series of even numbers begins 2, 4, 6, 8, ..., so 0 fits in if we extend the series backwards one place.)

The next one is fairly soon after 2/2/2000: 4/2/2000 and there are several more in February
2000. Can you tell me *how many even dates there are in February 2000*?

Can you tell me when the *previous even date* was
that only had only even digits in it before February 2000?
Hint: it was a

*very*long time ago.

#### What an odd day!

Interestingly, it was not too long ago that there was a date composed solely of
*odd digits* - an **odd date**. It was in November 1999. What dates in that month
were **odd dates**?

When is the next **odd date**? Hint: it is a *very* long time in the future.

So within 4 months we have had both dates that are solely even and purely odd dates.

Will it ever happen again within one person's lifetime?