Then they called one another in the morning.
They called on each other in the morning.
(Then) in the morning they called out to one another, saying
Then they called out one to another in the morning
So they called each other in the morning/daybreak
As they woke up they said:…
They then called out to each other at daybreak
So they called to one another at the break of dawn
Then as the day dawned, they started calling out one another
Meanwhile they called one to another at the break of dawn
Then they called out one to another as soon as the morning broke