Go to your 'Plugins' folder in the files of your server.
Go through your plugins until you find 'Skript'.
Enter the Skript folder and click on the 'Skripts' file. You should now see around 10 disabled Skript files. (If you are using the newer version of Skript)
Now drag and drop the 'PlayTime+.sk' file into the 'Skripts' file.
Go to Minecraft and run the command "/sk reload PlayTime+.sk"