Daeron's invention of his Runes is mentioned in The Grey Annals (in volume XI of The History of Middle-earth), but the dating there is rather vague. All we can say for sure is that they were devised some time after the Valian Year 1350 (that is, within about the last 1,400 solar years before the first rising of the Sun).

Tradition said that Daeron improved on his own original invention to produce the Angerthas Daeron, a more fully developed writing system. This tradition may have been in error, and some sources suggest that this system was actually developed rather later - probably in Second Age Eregion - and it is therefore open to question whether the later Angerthas should truly be considered Runes of Doriath.