So what have i done wrong here? trying to get a warning message from the server to warn players that night is coming

{
"EnableInGameTime-Timer": true,
"EnableRealTime-Timer": false,
"EnableTimerOnce": false,
"EnableTimerRepeat": false,
"InGameTime-Timer": {
"18:00:00": "say 'Night Cycle Approaching... Prepare For Zombie Spawns'"
},
"RealTime-Timer": {},
"TimerOnce": {},
"TimerRepeat": {}
}

"18:00:00": "say 'Night Cycle Approaching... Prepare For Zombie Spawns'"

change to

"18:00:00": "say Night Cycle Approaching... Prepare For Zombie Spawns"

This is what i have now, and it is still not displaying the message to server
{
"EnableInGameTime-Timer": true,
"EnableRealTime-Timer": true,
"EnableTimerOnce": true,
"EnableTimerRepeat": true,
"InGameTime-Timer": {
"18:00:00": "say Night Cycle Approaching... Prepare For Zombie Spawns"
},
"RealTime-Timer": {
"16:00:00": "command1 arg"
},
"TimerOnce": {
"command1 'msg'": 60,
"command2 'msg'": 120,
"command3 arg": 180,
"reset.timeronce": 181
},
"TimerRepeat": {
"command1 arg": 300,
"command2 'msg'": 300
}
}