Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Ask questions, find answers and collaborate at work with Stack Overflow for Teams. Ask questions, find answers and collaborate at work with Stack Overflow for Teams. Explore Teams Teams Q&A for work Connect and share knowledge within a single location that is structured and easy to search. In old books, people often use the spelling "to-day" instead of "today". When did the change happen? Also, when people wrote "to-day", did they feel, when pronouncing the word, that it contained two words, rather than a single concept? Five minutes of research brings... today O.E. todæge, to dæge "on (the) day," from to "at, on" (see to) + dæge, dative of dæg "day" (see day). Generally written as two words until 16c., after which it usually was written to-day until early 20c. Similar constructions exist in other Germanic languages (cf. Du. van daag "from-day," Dan., Swed. i dag "in day"). Ger. heute is from O.H.G. hiutu, from P.Gmc. hiu tagu "on (this) day," with first element from PIE pronomial stem ki-, represented by L. cis "on this side." The same applies to tomorrow and tonight, at least according to this dictionary. I grew up writing 'to-day' and 'week-end' (in 1950s' Britain). Common pairings of words seem, first, to be linked with a hyphen, then to become one word. I did not feel any differently about 'to-day' than I do these days about 'today'. Start asking to get answers Find the answer to your question by asking. Explore related questions See similar questions with these tags. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Site design / logo © 2025 Stack Exchange Inc; user contributions licensed under CC BY-SA . rev 2025.8.29.33370