In the world of videogames, highlighting the passage of time is an incredibly useful tool. In any form, be it day cycles, moon phases or internal calendars, time can add to immersion like virtually nothing else. Without much fanfare, it's become a key component of games that want to maintain the illusion of a persistent world. From periodically changing the color scheme to utilizing the clock on today's consoles and PCs, time mechanics have been evolving for the better since the very beginning.
As early as the original Super Mario Bros., game developers recognized that games could be less repetitive simply by taking away the perpetual daylight. While most of Super Mario Bros. took place during the day, there were occasional darkness-laden levels as well. The idea was hardly an immersion builder at this point, but it did lend the game a sense of variety. It was an idea that we still see today in mission-based games that feature some missions during the day and some at night.
A few years later, another NES title took a step further in its depiction of time with one simple phrase: "What a horrible night to have a curse." In Castlevania II: Simon's Quest, such a message would pop up every few minutes declaring the coming of day or night, and the game's color scheme would change to reflect this new state. While some players considered these messages more disruptive than immersive, others believed they lent the adventure a grander sense of scale than other games of that time (in which the story always seemed to take place over the course of a single day). This mechanic also acted as a storytelling device, as the towns became infested with zombies and the surrounding areas populated with more aggressive creatures during nighttime, thanks to Dracula's curse.
As the years went by, time mechanics in games evolved quickly and became more common. Games started to divide days into more discrete sections - instead of a binary day/night cycle, games would transition from the gray of early morning to the blue of midday, the orange of evening and, finally, the black of night. Eventually, games like Harvest Moon added a clock to the whole equation, scaled to the shorter day cycles of its world. Developers started to realize the ability time had to draw players into their games. When asked how long they've been playing Harvest Moon, players might have answered "12 days" when they really meant four hours.
Once games started to go 3D, that giant lens flare in the sky became another timekeeping tool at developers' disposal. Games like the Legend of Zelda: Ocarina of Time and Morrowind absorbed players in a world replete with sunrises and sunsets, nocturnal monsters and constellation-filled skies. Just imagine Ocarina of Time without that one simple ingredient: There would be no waiting for nightfall to sneak into Hyrule Castle, no Castle Town nightlife and no riding off into the sunset in Gerudo Valley. This seemingly superficial element brought the Zelda universe to life by allowing it to continually change without any input from players.