Option for Year Value in Lieu of Step 2.
As you now know, there are just six moving parts in the DOW method (or technique), but because it is a combination of formulas, tables (which have to be memorized), and process, there are many ways the same basic math can be expressed. The DOW method shown on this site is one, although I believe it is probably the simplest way to do it. However, if you are good at memorizing but lousy at arithmetic, you might want to consider two options for accomplisnmh step 2, the calculation for the value to add in for the Year.
The first option is to memorize the 240 numbers (some double in the leap years) in the Year values table (click here) for each of the 99 years in a century and the four different century values, 0, 5, 3 and 1, and that would be it. If that is too much to memorize you could memorize the 135 numbers (some double in leap years) for the century value of 0 (which just so happens to be the value for the 21st century, by the way), and then add in the additional value of 5, 3, or 1 for the other centuries when you need to. Or you could memorize only the 35 numbers (some double) for the ‘00 to ‘27 years in the 0-value century and then go through the math of subtracting out from the two-digit year the largest multiple of 28 to find the corresponding 00-27 year, and then adding in the century. Or you could memorize only the 28 numbers for the ‘00 to ‘27 years in the 0-value century, skipping the 7 double numbers for leap years, leaving that for you to figure when you have to and only then subtracting 1 in January and February. But if you go this last route, you’d still have to memorize 56 numbers (28 X 2, one for the years 00 to 27 also), in additional to doing the reduction arithmetic for the years 28-99 and adjusting for January and February in leap years. Whatever of these options you take, this is a lot of memorizing, and you may still involve some math depending upon which level you take. I would advise against this option, but it is an option .
The second option would be to memorize only the below 10 four-digit numbers (reading down the columns):
D/U | Decade (for row DV) or Unit Year (for row VE or VO | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
VD | Value for the Decade start year | 0 | 5 | 4 | 2 | 1 | 6 | 5 | 3 | 2 | 0 |
VE | Additional value for unit year in Even Decades start year | 0 | 1 | 2 | 3 | 5 | 6 | 0 | 1 | 3 | 4 |
VO | Additional value for unit year in Even Decades start year | 5 | 6 | 1 | 2 | 3 | 4 | 6 | 0 | 1 | 2 |
Note: Additional values for the leap years within the decade bolder and slightly larger than the others. But also notice that those years are two numbers higher than the numbers in the previous columns.
The numbers in the first row represent, alternately, the first digit of the decade year (D) within a century (e.g., ‘00, ‘10, ‘20, ‘30, etc.) when that row applies to the second row, and then the units (U) digit of the year within a decade, (e.g., ‘00, ‘01, ‘02, ‘03, etc.) when that row applies to the third and fourth rows.
The second row, the VD value, refers to the basic value for the Decade in the first row (but not that decade year).
The next two rows apply to the Unit digit of the two-digit year (also alternately depicted in the first row (D/U). If the decade year is an even number (e.g., starting with ‘00, ‘20, ‘40, etc.) the even (VE) row applies. If the decade year is an odd number (e.g., ‘10, ‘30, ’50, etc.) the Odd (O) row applies. The appropriate additional value for the unit year within that decade (the second number of the two-digit year) from either of theses two rows is added to the basic value for the decade to get the value for the year.
After you add the two values together, if the value for the century is not 0, you still need to add the value for that other non-0 century (5, 3, or 1) and if the month is January or February and the year is a leap year, subtract 1 from the result. As the note under the table says, leap years for the even decade years occur at the 0, 4 and 8 years; for the odd decade years at the 2 and 6 years.
To repeat, here’s how this table works: Add the basic decade value in the second (DV) row for the decade and the appropriate value for the unit year within that decade from either the third (for an even decade, VE) or the fourth (for an odd decade, VO) row. Then add in the value for the century and subtract 1 if the year is a leap year and the month is January or February.
Here’s an example: What is the year value January X, 2005? The decade here is the 0 decade, which is an even number, and the unit year is 5, so the value for the decade from the second (DV) row is 0, and the value for the unit year in an even decade is 6 and so 0 plus 6 equals 6. Since the century value is 0, we have to add nothing, and since the year is not a leap year we can ignore any leap year adjustment of -1, so the final value is 6. If the year happened to be a leap year and the month of the date was a January or February, we would have to subtract 1 from the result (but not in years not evenly divisible by 400). Don’t worry about subtracting out the largest multiple of 7 from the result because that will be done in step 3.
