How to find out what year a Honda Accord motor is?

I'm doing a motor and tranny swap in my car and I need to know how to find out what year a motor is so I can match up an ecu for it. Any help is appreciated.

I do not know the answer to your question. The vehicle VIN number will tell you all of the information about the vehicle. Use the VIN decoder: http://www.autohausaz.com/honda-auto-par…
Other than that, the engine ID code as well as the motor's serial number, is engraved onto every single Honda engine block. You can find the code on the exhaust side of the motor, to the left of the exhaust manifold, up near where the block meets the head. See the picture below.
Depending on the origin of the motor (Japanese market versus American or other non-Japanese markets), the engine ID code will be either four or five characters long** (ex: B16A, or D16Z6). Typically, the seven digit serial number will be engraved below the engine ID code. On some older models, the engine's ID code and serial number can also be found on the engine bay identification plate, typically printed together on one line.
Note: This is the typical code location for 4 cylinder Honda engines; for V6 engines or other variants, the location of the engine ID code and serial number may vary.
Most people are aware that there are several different series of Honda engines (B-Series, D-Series, and H-Series for example). What you may not realize however, is that every Honda engine has its own specific identification code which tells us information about the motor.
Honda's engine codes are typically four or five characters in length. Japanese market (JDM) motor ID codes are always four characters long, while US spec (USDM) or other export motor codes usually contain five characters.
The first character of a typical Honda engine code is usually a letter, which denotes the series of the engine. The next two characters are typically numbers, which denote the motor's displacement in liters. The fourth character is typically a letter, which denotes the particular model of the engine within the engine series.
Take for example the B18C, a very popular tuner engine originally found in the 1994-2001 Integra. The "B" indicates that the motor is a member of the B-Series engine family, the "18" indicates that the motor displaces 1.8 liters, and the "C" indicates the motor's specific model within the 1.8 liter B-Series engine group (as opposed to a B18A or B18B). Another example would be the H22A motor found in Preludes and some Japanese Accords. In this case, the engine is part of the H-Series, displaces 2.2 liters, and is the "A" model within the H-Series family of engines.
As mentioned earlier, non-Japanese (USDM, UK, etc.) Honda engine codes will often contain a fifth character. A USDM B16 engine code might read "B16A2" for example, as opposed to the "B16A" stamp on a JDM motor. The meanings of these numbers are not specifically clear; most likely they are simply used to differentiate variants of the same motor sold in different regional markets.
One exception to the typical Honda engine code format is the ZC-Series of engines found in some late 80s and early 90s Civics, CRXs, and Integras (Japanese market only). The ZC motors are actually an offshoot of the D-Series. Instead of using the standard four character engine code format however, the ZC blocks are stamped with a simple "ZC" designation.
Edit: This article may help