The mod pack adds an custom couter in your actionbar (over your hotbar). The counter counts in ingame days minutes and seconds. So for example the mod could display: Day 34 [15:47]. Every day has 24 Hours (First number in the square brackets) and every hour has 60 minutes (Second number in the square brackets). If you create a world the mod doesnt start on day 0 like the f3 menu instead it starts on day 1. Although the mod works with the /tick command it doesnt work with the /time command since the mod counts in ticks.