Time
It must be a single-precision floating-point number suffixed with a unit. It must be not less than 0 gameticks. The time is set to the closest integer after unit conversion to gametick. For example. .5d is same as 12000 gameticks.
Units include:
[amount][unit]
t
: a single gametick, 1 tick;s
: a second, 20 gameticks;d
: an in-game day, 24000 gameticks;
Minecraft Wiki time for more information.