Better timezones?

Let’s say we’re doing Hong Kong/Beijing to London. That’s -8. Just use a fat lady with a bowel hat to symbolise it. No problem.

However, is there a system that encompasses all combinations? There are 24hrs in the day. Memorising them all is 24x24. What if there was a mental maths technique whereby doing maths with objects creates new objects, which are the answer?

You don’t need to memorize all 24x24 combinations (in fact there are much more, as e.g. India is UTC+0530, Nepal is UTC+0545, and various countries have daylight saving at different times, so London/Sydney has three different values throughout the year).

Just memorize the offsets from UTC+0000 (London in January).

Furthermore you don’t really need to memorize them as random data. India is obviously +0500 or +0600 or something like that, given its geographical position east. I don’t know what Japan is but I can guess +0900 just because it’s slightly east of China.

So if you want to use a memory palace technique, you could be as minimalist as having 3-4 rooms, each with a different setting/feature, and placing the country/city in the correct one.

So with 4 rooms, every place with +0000, ±0400, ±0800 can go in room 4, ±0100, ±0500 and ±0900 in room 1, etc.

Then when you think of e.g. Costa Rica, you remember it was in room 2, and from its location it’s clearly -0600 rather than -1000 or -0200.

You’ll need something to modify the half-hour offsets (and deal with Nepal…) but that is straightforward.

Finally, to get the difference between e.g. Costa Rica and Japan, you just remember Costa Rica is -0600 and Japan is +0900, and therefore the difference is 15 hours.

The trickest part is the daylight savings part since it changes through the year, but if you remember the wintertime offsets, then at least you can ±1 or ±2 hours in Summer to get it right.

Or if your method fails sometime, you can Google e.g. “time difference costa rica tokyo”.


This is really good for anyone who has basic maths for 1-24 and bad geography.

Personally, I’m the other way round. I know the location of every city and can get the timezone right most of the time.

But 7 minus 3 takes me 4 seconds to calculate.
I really am that dumb.

Okay—in this case it looks like you are missing the additions and subtractions from memory. For mental maths, tt’s essential to know the times tables (from 2x2 to 9x9) but it’s also essential to know the single-digit additions from 1+1=2 to 9+9=18, and to be able to do these backwards too, e.g. both 3+4=7 and 7–3=4.

These should be directly from memory (don’t use memory palaces etc. for this). If you need help training these, let me know!