Something like this
CMD:settime(playerid, params[])
{
new time, string[128];
if(sscanf(params, "i", time)) return SendClientMessage(playerid, -1, "Usage: /settime [time]");
if(time > 24 || time < 0) return SendClientMessage(playerid, -1, "Error: Invalid time!");
SetWorldTime(time);
format(string, sizeof(string), "Time set to %d", time);
SendClientMessage(playerid, 0x00FF00FF, string);
return 1;
}
or
CMD:setnight(playerid, params[])
{
SetWorldTime(0); //midnight
SendClientMessage(playerid, 0x00FF00FF, "Time set to midnight.");
return 1;
}