If you plan to retire at some point in the future but have no idea when, this is an example of when you plan to retire someday.
Usage Note: The adverbs someday and sometime express future time indefinitely: We'll succeed someday. Come sometime. Let's meet sometime when your schedule permits. This sense can also be conveyed by some day and some time. The two-word forms are always used when some is an adjective modifying and specifying a more particular day or time: Come some day (not someday) soon. Choose some day (not someday) that is not so busy. See Usage Note at sometime.
- Someday, you might need these lessons.
- Someday, if you're a good boy, I'll let you listen.
- Someday, when there is a concert, I would love to take you to Tanglewood.
- I plan to tell them someday, but I'm not ready yet.
- His production consists of two elaborate complementary lists: the one describing sign-pictures and giving their meanings, the other cataloguing ideas in order to show how they could be expressed in hieroglyphic. Each seems to us to be made up of curious but perverted reminiscences eked out by invention; but they might someday prove to represent more truly the usages of mystics and magicians in designing amulets, &c., at a time approaching the middle ages.