I've set the format for the UI and that works great, but the chat message still uses seconds.

Is it possible to have the chat messages use the same time format as the UI does?

Please, provide your lang file here. Basically both the ui and chat messages share the same format described in the docs.

2CHEVSKII

Please, provide your lang file here. Basically both the ui and chat messages share the same format described in the docs.

{
"Chat prefix": "Server Restart: ",
"No permission": "<color=#d9420f>You</color> have no permission to use this command",
"Kick reason": "Server is restarting",
"Help message": "/sr <color=#1a97ba>[command]</color> <color=#1aba8f>[arguments]</color>\nCommands: <color=#1a97ba>help</color>, <color=#1a97ba>status</color>, <color=#1a97ba>restart</color>, <color=#1a97ba>cancel</color>\nTo get information about command usage, type '/sr <color=#1a97ba>help</color> <color=#1aba8f>[command]</color>'",
"Help message: Help": "/sr <color=#1a97ba>help</color> <color=#1aba8f>[command]</color> - Outputs general help message or command usage help if command is specified",
"Help message: Status": "/sr <color=#1a97ba>status</color> - Outputs current restart status",
"Help message: Restart": "/sr <color=#1a97ba>restart</color> <color=#1aba8f>[time]</color> - Initiates new restart process\nTime must be in one of the following formats:\n<color=#77ba20>123</color> - delay before restart in seconds\n<color=#77ba20>123</color><h|m|s> - delay before restart in <hours|minutes|seconds>\n<color=#77ba20>1</color>h <color=#77ba20>2</color>m <color=#77ba20>3</color>s - delay before restart in hr+min+sec, all optional\n<color=#77ba20>1</color>:<color=#77ba20>23</color> - schedule restart on 1:23 (24hr format)",
"Help message: Cancel": "/sr <color=#1a97ba>cancel</color> - Cancels current restart process",
"Restarting already": "Cannot do restart - already restarting. Use '/sr <color=#1a97ba>status</color>' to get info about current restart process, or try '/sr <color=#1a97ba>cancel</color>' to cancel current restart before starting new one",
"Not restarting": "Cannot cancel restart - plugin does not perform a restart currently.",
"Cancelled successfully": "Restart was successfully cancelled",
"Restart reason: Timed": "Planned",
"Restart reason: Oxide update": "New Oxide update is out",
"Restart reason: Command": "Command from <color=#dbc30b>{0}</color>",
"Restart reason: API call": "API call from <color=#dbc30b>{0}</color>",
"Announcement: Restart initiated": "The Server will be restarted in <color=#a4db0b>{0}</color> seconds.",
"Announcement: Countdown tick": "<color=#a4db0b>{0}</color> seconds left before server restart",
"Announcement: Restart cancelled": "Server restart was cancelled",
"Restart initiated": "Restart initiated successfully",
"Status: Restarting": "Server is restarting, <color=#a4db0b>{1:0}</color> seconds left",
"Status: Restarting (global.restart)": "Server is restarting natively",
"Status: Restart planned": "Server restart planned on <color=#a4db0b>{0:hh\\:mm}</color> (<color=#a4db0b>{1:0}</color> seconds left)",
"Status: No planned restarts": "Server is not restarting, no planned restarts found",
"UI title": "Server Restart",
"UI countdown format": "{0:sfmt::<hr?+ hrs> <min?+ mins> <sec?+ secs>} left"
}

Bumfuzzler

{
"Chat prefix": "Server Restart: ",
"No permission": "<color=#d9420f>You</color> have no permission to use this command",
"Kick reason": "Server is restarting",
"Help message": "/sr <color=#1a97ba>[command]</color> <color=#1aba8f>[arguments]</color>\nCommands: <color=#1a97ba>help</color>, <color=#1a97ba>status</color>, <color=#1a97ba>restart</color>, <color=#1a97ba>cancel</color>\nTo get information about command usage, type '/sr <color=#1a97ba>help</color> <color=#1aba8f>[command]</color>'",
"Help message: Help": "/sr <color=#1a97ba>help</color> <color=#1aba8f>[command]</color> - Outputs general help message or command usage help if command is specified",
"Help message: Status": "/sr <color=#1a97ba>status</color> - Outputs current restart status",
"Help message: Restart": "/sr <color=#1a97ba>restart</color> <color=#1aba8f>[time]</color> - Initiates new restart process\nTime must be in one of the following formats:\n<color=#77ba20>123</color> - delay before restart in seconds\n<color=#77ba20>123</color><h|m|s> - delay before restart in <hours|minutes|seconds>\n<color=#77ba20>1</color>h <color=#77ba20>2</color>m <color=#77ba20>3</color>s - delay before restart in hr+min+sec, all optional\n<color=#77ba20>1</color>:<color=#77ba20>23</color> - schedule restart on 1:23 (24hr format)",
"Help message: Cancel": "/sr <color=#1a97ba>cancel</color> - Cancels current restart process",
"Restarting already": "Cannot do restart - already restarting. Use '/sr <color=#1a97ba>status</color>' to get info about current restart process, or try '/sr <color=#1a97ba>cancel</color>' to cancel current restart before starting new one",
"Not restarting": "Cannot cancel restart - plugin does not perform a restart currently.",
"Cancelled successfully": "Restart was successfully cancelled",
"Restart reason: Timed": "Planned",
"Restart reason: Oxide update": "New Oxide update is out",
"Restart reason: Command": "Command from <color=#dbc30b>{0}</color>",
"Restart reason: API call": "API call from <color=#dbc30b>{0}</color>",
"Announcement: Restart initiated": "The Server will be restarted in <color=#a4db0b>{0}</color> seconds.",
"Announcement: Countdown tick": "<color=#a4db0b>{0}</color> seconds left before server restart",
"Announcement: Restart cancelled": "Server restart was cancelled",
"Restart initiated": "Restart initiated successfully",
"Status: Restarting": "Server is restarting, <color=#a4db0b>{1:0}</color> seconds left",
"Status: Restarting (global.restart)": "Server is restarting natively",
"Status: Restart planned": "Server restart planned on <color=#a4db0b>{0:hh\\:mm}</color> (<color=#a4db0b>{1:0}</color> seconds left)",
"Status: No planned restarts": "Server is not restarting, no planned restarts found",
"UI title": "Server Restart",
"UI countdown format": "{0:sfmt::<hr?+ hrs> <min?+ mins> <sec?+ secs>} left"
}

From what I can see - you did not format chat messages with the same format as UI. Do this for the messages you want and it will work.

Ahhhhhhhhh I didn't see that there :) It's in the 

"Status: Restart planned": "Server restart planned on <color=#a4db0b>{0:hh\\:mm}</color> (<color=#a4db0b>{1:0}</color> seconds left)",​

Thanks.