The song has received universal acclaim.

In 2010, « The Day Before You Came » was positively reviewed by Stephen Emms for The Guardian. Emms opined that the song is a « forgotten masterpiece », and that the mixture of "the genuine sense of loss in Agnetha’s voice, Frida’s operatics, a moodily expressionist video and plaintive synths as omnipresent as the rain ’rattling’ on the roof...carries a sense of foreboding almost unparalleled in pop music." Emms continued to state that "the track’s power lies in its layering of boredom and grandeur, transience and doom. It combines a rising sense of melancholy, both in its melody and production, with wistful, nostalgic lyrics." Emms also interpreted that the pathos is "heightened by an extended funereal instrumental coda which acts as one big question mark, leaving us with the feeling that this is not just a meditation on the quotidian but something greater, existential even. Is this imagined relationship, like the band itself, doomed ?" He argues in his review that, in his opinion, it is unlikely that the "complexity [in The Day Before You Came could be replicated in] ABBA’s [then] rumoured comeback single" [3]

Kultur describes it as ABBA’s « darkest song » and their "very last - and best - recording« . It noted that the »happy and well-behaved Abba in [its] last creative moment managed to portray how the romantic dream - which so incredibly strongly permeates our entire culture, especially through advertising - might as well mean destructiveness and suffocating nightmare, that was the last thing many expected [ABBA to do] a few years earlier".[6]

One Week II One Band said « There is something about this long, strange, monotonous, chorus-free ABBA song which gets to people. »[29]

The song has been described as : « mesmerising [and] hypnotic »,[41] « [a] beautiful ballad »,[9] « [a] stark, superb swansong »,[42] and « [the] strangest and maybe best of all [from ABBA’s catalogue] ».[26] 80s45s describes the song as « poignant and quite profound » and says the « bleak lyrics about love and desire » in songs such as The Day Before You Came is surprising, due to ABBA often being "associated with Eurovision cheesiness and sequined kitsch« .[23] Evening Standard music critic John Aizlewood referred to the »detailed résumé of the ordinariness of someone’s life« as »desperately unhappy".[43]

In a critique of the 2012 album The Visitors [Deluxe Edition], in which The Day Before You Came is a bonus track, Tom Ewing of Pitchfork describes the song as the « career highlight » for ABBA. He says that the song « shares its themes with much of the album », despite being « on paper, a happier song » than the title track. He suggests that the song holds the view that "life is unstable, happiness may be fleeting, and your world can be instantly and forever overturned", and comments that these « strong, resonant ideas » are the perfect way for the band to have ended their career, and serves as an almost "spectral, uneasy premonition...of [ABBA’s] own demise".[27] Rudolf Ondrich analysed the bonus track by saying "The Day Before You Came is by far the saddest song I know within the pop repertoire", and puts this down to it being one of the last ABBA recordings, commenting that « the late output of many artists » is wonderful as it is like "they realize that they cannot create music forever, that their time is nearly up, and so they go into emotional hyperdrive", causing them to create music that « touches [him] in ways [he] cannot describe », this song being no exception.[44]

Norman Lebrecht of Bloomberg suggests that The Day Before You Came, along with I Am Just a Girl and The Winner Takes It All, are "commercially formulaic as anything cooked up in a dark studio since the dawn of pop charts« , and are delivered with a »one musical line bent crescent-shaped in ironic detachment« as opposed to the »belting frenzy of pop style" of some of their other songs.[45]

After contemplating on the « complete choir » that is created just by ABBA’s voices, Robert Verbeek in his work ABBA & Me says that "even when they are each other’s backing vocals they sound terrific« , and ponders on what »The Day Before You Came [would] be without Frida’s background opera-like singing". He describes the song, along with The Winner Takes It All, Eagle, and I’m A Marionette, as « musical masterpieces », which show ABBA’s extraordinary growth from its humble origins in simple pop songs like Nina, Pretty Ballerina and Ring Ring.[5]

In his work ABBA : Let The Music Speak, Christopher Patrick refers to The Day Before You Came as « ABBA’s swansong » and an « electronic masterpiece ». He describes it as "one of the saddest ABBA songs of all« and »like a magnificent piece of embroidery". He states that « the melancholy is so deeply engrained in [the song’s] fabric », and says the « meticulous attention to detail in the vocals and production » is « intricately beautiful ». He comments that the approach, involving giving Agnetha lead vocal and make Frida essentially a backup singer, « serves the song very well », adding that "Agnetha’s solitary vocal accentuates th[e] sense of loneliness and isolation« . He says that »the resulting performance« is both emotional and effective, and »is perfectly matched to the production« . He says that into the »dying fade« , there is a »faint haze of farewell" [4]