Error message not match the error faced

[GERARDJM018]

The image above is taken when I use this command: 'edit i:1 c/mon: 8-10, 10-12 tue: 11-13 lki: 11-13'. Although the error is on the day format, it seems it recognizes it as 'period' error. Could provide new error message for the day format error or make a more generalized error message (Contains the format of the full command. Although this works, it is not recommended).