Soo'jen was a month in the Klingon year, in their civilization's measurement of time. (ST novel: Excelsior: Forged in Fire)

Months of the Year
Earth months (Gregorian calendar)	January • February • March • April • May • June • July • August • September • October • November • December
Qo'noS months	Doqath • Lo'Bral • Maktag • Merruthj • nay'Poq • Soo'jen • Xan'lahr
Vulcan/Romulan months	Tasmeen • Haraveen • Sharveen • K'ri'Brax • re'Ti'Khutai
Ferenginar months	Glorpober