Again about articles ((
I am reading Harry Potter and the Philosopher's Stone by J. K. Rowling and in the chapter three (THE LETTERS FROM NO ONE) I see such paragraphs:
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Next morning at breakfast, everyone was rather quiet. Dudley was in shock. He’d screamed, whacked his father with his Smelting stick, been sick on purpose, kicked his mother, and thrown his tortoise through the greenhouse roof, and he still didn’t have his room back. Harry was thinking about this time yesterday and bitterly wishing he’d opened the letter in the hall. Uncle Vernon and Aunt Petunia kept looking at each other darkly.
.....
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The repaired alarm clock rang at six o’clock the next morning. Harry turned it off quickly and dressed silently. He mustn’t wake the Dursleys. He stole downstairs without turning on any of the lights.
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In the first case - "Next morning at breakfast..." - without "THE" before "morning"
In the second case - "...at six o’clock the next morning..." - with "THE" before "morning"
Why?