I mean, you can do like this
PHP Code:
public void OnPluginStart()
{
HookEvent("round_start", Event_RoundStart);
}
public void Event_RoundStart(Event event, const char[] name, bool dontBroadcast)
{
CreateTimer(30.0, TimerSetSpeed);
}
public Action TimerSetSpeed(Handle timer)
{
ServerCommand("sm_speed @t 0.5");
}