Yes, we can narrow down and prepare for the time of the year of His coming by observing the Day of Trumpets as commanded in the Torah, though the exact year is more difficult to determine. He desires our love for Him all the time and not just the last minute.
The reason why we cannot know the exact day and hour is because He will return on the Day of Trumpets:
Joel 2:15 Blow the trumpet in Zion, sanctify a fast, call a solemn assembly:
Joel 2:16 Gather the people, sanctify the congregation, assemble the elders, gather the children, and those that suck the breasts: let the bridegroom go forth of his chamber, and the bride out of her closet.
1 Cor 15:52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
1 Th 4:16 For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first:
Rev 1:10 I was in the Spirit on the Lord's day, and I heard behind me a loud voice like the sound of a trumpet,
The Day of Trumpets is the only Appointed Time of YHVH of Leviticus 23 that occurs precisely at the the appearing of the New Moon signifying the beginning of the month.
Unlike all other Appointed Times and Feast Days which are counted a prescribed number of days from the appearing of the New Moon which can be determined and known.
Day of Trumpets begins at the very sighting of the New Moon, the first day of the month:
Lev 23:24 "Speak to the sons of Israel, saying, 'In the seventh month on the first of the month, you shall have a rest, a reminder by blowing of trumpets, a holy convocation.
Day of Atonement, ten days after the New Moon:
Lev 23:27 "On exactly the tenth day of this seventh month is the day of atonement; it shall be a holy convocation for you, and you shall humble your souls and present an offering by fire to the LORD.
Feast of Booths / Tabernacles, fiftteen days after the New Moon:
Lev 23:34 "Speak to the sons of Israel, saying, 'On the fifteenth of this seventh month is the Feast of Booths for seven days to the LORD.
The Eighth Day, the day after at the ending of Tabernacles:
Lev 23:36 'For seven days you shall present an offering by fire to the LORD. On the eighth day you shall have a holy convocation and present an offering by fire to the LORD; it is an assembly. You shall do no laborious work.
Passover, the fourteenth day after the New Moon:
Lev 23:5 'In the first month, on the fourteenth day of the month at twilight is the LORD'S Passover.
Unleavened Bread, the fifteenth day after the New Moon:
Lev 23:6 'Then on the fifteenth day of the same month there is the Feast of Unleavened Bread to the LORD; for seven days you shall eat unleavened bread.
First Fruits, the first day of the week after the 7th day Sabbath following Passover:
Lev 23:11 'And he shall wave the sheaf before the LORD for you to be accepted; on the day after the sabbath the priest shall wave it.
Shavuot / Pentecost, fifty days from First Fruits:
Lev 23:16 'You shall count fifty days to the day after the seventh sabbath; then you shall present a new grain offering to the LORD.
Isa 66:23 "And it shall be from new moon to new moon And from sabbath to sabbath, All mankind will come to bow down before Me," says the LORD.