Joel 2:12 about fasting

I asked elsewhere if Yahweh ever commanded fasting on the Day of Atonement.

I was given Joel 2:12
"Even now," declares the Lord, "return to me with all your heart, with fasting and weeping and mourning."

And I will add Joel 1:14
Declare a holy fast; call a sacred assembly. Summon the elders and all who live in the land to the house of the Lord your God, and cry out to the Lord.
And Joel 2:15
Blow the trumpet in Zion, declare a holy fast, call a sacred assembly.


a. Was Joel 2:12 and 2:15 a commandment for the Day of Atonement?
b. Was fasting the focus in the context?
c. Was fasting a private act in Joel 2:12? For that matter, was it in Joel 1:14 and 2:15?
d. Was either Joel 1:14, 2:12 and 2:15 for a specific day?
e. If fasting were to be a physical action commanded by Yahweh, would weeping, mourning, sacred assembly, blowing the trumpet, crying out to the Lord be physical actions too?
f. What happened?

Some said Joel was written before Isaiah. If that's the case we know the Israelites got it all wrong and required Yahweh's rebuttal through Isaiah 58.
If Joel was written the same time as Isaiah, what should the readers do after they heard both prophets? Would it be a personal choice of physical fasting as in Joel and spiritual fasting as in Isaiah? I would say no.
If Joel was, ever so unlikely, written after Isaiah, then the meaning of fasting should be very clear, shouldn't it?

We know blowing the trumpet is a metaphor for warning. If one does not know I will provide proofs.
What does fasting mean?

There were other acts commanded by Yahweh through Joel:

1:5 Wake up, you drunkards, and weep! Wail, all you drinkers of wine; wail because of the new wine, for it has been snatched from your lips.

1:8 Mourn like a virgin in sackcloth grieving for the husband of her youth.

1:13 Put of sackcloth, O priests, and mourn; wail, you who minister before the altar. Come, spend the night in sackcloth, you who minister before my God; for the grain offerings and drink offerings are withheld from the house of your God.

If the verses regarding fasting in Joel were evidences for physical fasting on the day of atonement (which is not), should not the above acts be physically followed as well?

Was Joel 1:5 applicable for alcoholics and wine drinkers only?

Read Isaiah 29:9-10 Be stunned and amazed, blind yourselves and be sightless; be drunk, but not from wine, stagger, but not from beer. The Lord has brought over you a deep sleep; He has sealed your eyes (the prophets); he has covered your heads (the seers).