I simply discovered an previous riddle that was despatched to me years in the past. I wasn’t in a position to remedy it then and have not been in a position to remedy it now both. Can you assist me out?

This is what he wrote:

“I made this riddle some time again within the 00s (I’ll provide you with this one ;)) after I was within the army, however sending it to you now;

I’m very particular. Split me in half and also you get the primary half – one very particular and one not particular in any respect. Split me in three and also you get the second half – one very particular and two particular. Split me in 4 and none of us are the identical but particular.

Exactly when did I make this puzzle? Give me the complete reply.”

What did he imply by very particular, particular and never particular. How are we suppose to search out out precisely when he created it?