This is from the descr_events file the dates are in YEARS after game start. If there are two numbers it is random between those numbers.
Code:
; -------------- CUSTOM EVENTS --------------
event historic STONE_CASTLES
;TRUE TIME date 35 85
date 35 65
;(c. 1140 AD)
event historic CONCENTRIC_CASTLES
;TRUE TIME date 165 215
date 175 205
;(c. 1270 AD)
event historic LIQUOR
;TRUE TIME date 145 195
date 145 195
;(c. 12th century)
event historic PAVISE_SHIELDS
;TRUE TIME date 255 285
date 245 295
;(c. 14th century)
event historic MOUNTED_CROSSBOWS
;TRUE TIME date 155 185
date 145 195
;(c. 13th century)
event historic BATTLE_ASSASSINS
;TRUE TIME date 120 170
date 130 160
;(c. Early 13th century)
event historic TEUTONIC_ORDER
;TRUE TIME date 245 295
date 245 295
;(c. 1351-1382)
event historic KNIGHTS_TEMPLAR
;TRUE TIME date 95 145
date 95 145
;(c. 12th and 13th centuries)
event historic ST_JOHNS_CHAPTER
;TRUE TIME date 195 245
date 195 245
;(c. 1291 AD)