We do not know the day or time our Lord will return to the earth. Yet, since our Lord promised he would return to gather his flock, it is wise to consider the following quote from Jesus to Saint Faustina regarding end times:
(My daughter) Speak to the world about My mercy; let all mankind recognize My unfathomable mercy. It is a sign for the end times; after it will come the day of justice. While there is still time, let them have recourse to the fount of My mercy; let them profit from the Blood and Water which gushed forth for them.” Diary, 848 (cf., John 19:34)
“You will prepare the world for My final coming.” Diary, 429
“Write this: before I come as the Just Judge, I am coming first as the King of Mercy.” Diary, 83
“Write: before I come as a just Judge, I first open wide the door of My mercy. He who refuses to pass through the door of My mercy must pass through the door of My justice…” Diary, 1146
“Secretary of My mercy, write, tell souls about this great mercy of Mine, because the awful day, the day of My justice, is near.” Diary, 965
“Before the Day of Justice I am sending the Day of Mercy.” Diary, 1588
“…I am prolonging the time of mercy for the sake of sinners. But woe to them if they do not recognize this time of My visitation. My daughter, secretary of My mercy, your duty is not only to write about and proclaim My mercy, but also to beg for this grace for them, so that they too may glorify My mercy.” Diary, 1160
(Words of the Blessed Virgin Mary, Mother of Mercy, to St. Faustina): “…you have to speak to the world about His great mercy and prepare the world for the Second Coming of Him Who will come, not as a merciful Savior, but as a just Judge. Oh, how terrible is that day! Determined is the day of justice, the day of divine wrath. The angels tremble before it. Speak to souls about this great mercy while it is still the time for granting mercy.” Diary, 635