Order by problem

Hello,

I have a table with a field called 'time' which is type char.

The data which goes into this field is 1am, 2am, 3am, 4am ,5am, 6am, 7am, 8am ,9am, 10am, 11am, 12noon, 1pm, 2pm, 3pm, 4pm,5pm, 6pm, 7pm, 8pm, 9pm, 10pm, 11pm, 12mid.

As users enter the data the order can go out of sequence, so I want to be able to sort the order to go as above for each day.

Is there a way of doing custom ordering by number, then letter of data in the same field.
or any other suggestions are welcome.

Thanks
GoongSuggestion: Store military time (00:00-23:00) and they will sort fine. Then, create a method in the UI that will display that value in a reasonable format.