OED gives this as both hyphenated and not. I note that Tolkien hyphenated “breakfast-time”, “tea-time”, and “supper-time” but not “lunchtime”.
- 19.036 It was now nearly lunchtime,
OED gives this as both hyphenated and not. I note that Tolkien hyphenated “breakfast-time”, “tea-time”, and “supper-time” but not “lunchtime”.