It can be hard. Sixty seconds is a minute. Sixty minutes is an hour. And 24 hours is a day, and seven days is a week. When you’re trying to do math with time, it’s hard.
Metric seconds is easy. It’s time measured in seconds using the standard metric units that are easy. The zero point is midnight January 1, 1970, the "start of time" for UNIX and other computer systems. And there are no time zones in metric time.
In metric time, seconds are the base unit. Then the regular metric multipliers are used: kilo, Mega, Giga, etc. We can use “hecto” for 100 seconds to have something close to a minute. Kiloseconds, 1000 seconds, are about 16 minutes long so 3.6 ksec is an hour and 86.4 ksec is a day.
Science fiction has used metric time. Some examples are Vernor Vinge’s books A Fire on the Deep and Deepness in the Sky and Charles Stross’s books Glasshouse, Accelerando, and Neptune’s Brood. Also Robert Forward and Iain M. Banks used metric time.
We won't abandon minutes and hours anytime soon. We’re all used to them. We won't start saying things like “I’ll be right with you, give me a hectosec.” For scientific and engineering measurements, kiloseconds, Megaseconds, and Gigaseconds might just make a lot of sense. Besides, trying something new is fun.