Friday – the finest working day carries a goddess’s name. But whose? Some swear by Freya, others by Frigg. The answer is surprisingly tangled, and it leads straight into one of the great debates of myth scholarship.
That Friday is named after a Germanic-Norse goddess is beyond doubt. It is the day of love – but in the Germanic heavens, love wears two faces.
Our weekday names come from the Roman planetary calendar. Friday was dies Veneris, the day of the love-goddess Venus – you can still hear it in French (vendredi) and Italian (venerdì). When the Germanic peoples adopted this calendar, they translated the Roman gods into their own; scholars call this the interpretatio germanica. For Venus, goddess of love, they inserted their own love-goddess. Thus arose *Frijjōdag, the „day of Frijjō".
Linguistically the trail leads fairly clearly to Frigg. In Old High German the day is Frîatac or Frîjetac – from which comes our German Freitag. In Old English it was Frīgedæg (today Friday), in Old Frisian Frīadei, in Middle Low German Vrīdach. All these forms go back to the West Germanic goddess Frija – the figure who lives on in the North as Frigg, Odin’s wife, mistress of marriage, motherhood and foresight. For Freya, by contrast, Old High German gives no evidence as patron of the weekday.
That Frija really was a venerated West Germanic goddess is shown by one of the very oldest German-language texts – the Second Merseburg Charm (9th century). There the goddesses together heal a horse’s wrenched leg:
“Then Sinthgunt charmed it, and Sunna, her sister; then Frija charmed it, and Volla, her sister …”— Second Merseburg Charm (9th c.), after a public-domain rendering
So where does the widespread conviction come from that Friday belongs to Freya? For one thing, Freya is simply the more famous goddess: the lady with the cat-drawn chariot, the necklace Brísingamen and the falcon cloak, who takes half the slain to her field Fólkvangr. For another, the modern Scandinavian languages often gloss the day – fredag – as „Freyja’s day", and a few medieval Icelandic scribes already wrote Freyjudagr. Catchy and popular – but not the root of the German and English weekday name.
And here it gets truly interesting, because this is exactly where the neat distinction blurs. Many scholars suspect that Frigg and Freya were originally a single goddess who only split apart later – reconstructed as Proto-Germanic *Frijjō. The clues are striking: both are goddesses of love. Both own a feather cloak for flying. And both are bound to a husband whose name begins with Óð- – Frigg with Odin (Old Norse Óðinn), Freya with the mysterious, ever-absent Óðr. Both weep for a distant man. That hardly looks like coincidence.
The other camp pushes back – above all on language. Frigg derives from the root „to love / beloved" (Proto-Germanic *frijaz „free, dear"), whereas Freyja simply means „Lady" (from *frawjōn „lord"; the male counterpart is Freyr, „Lord"). Two different names, and most linguists reject a common origin for them. The myth scholar Stephan Grundy sums up the dilemma honestly: whether Frigg and Freya were once one goddess is hard to decide – made harder by the scarcity of pre-Viking-Age evidence about Germanic goddesses. In short: unresolved.
Curiously, the actual Viking world did not know „Friday" as a planetary day at first – the numbered seven-day week arrived only with Christianity. Old Norse frjádagr is borrowed from West Germanic. Later the Church in Iceland even replaced the name with the sober föstudagur, the „fasting day". In the rest of Scandinavia, though, fredag stuck – the day of the goddess, whatever her name may be.

Freya – Goddess of Love · All the gods at a glance · Odin · Nerthus · Rune lexicon.
Second Merseburg Charm (9th c., public domain); Rudolf Simek, Dictionary of Northern Mythology; Jacob Grimm, Teutonic Mythology; Stephan Grundy on the Frigg–Freyja question; etymological dictionaries on the weekday name (OHG Frîatac, OE Frīgedæg). On the interpretatio germanica of the planetary weekdays.