Examples:
It’s = It is
“It’s my bedtime.”
“It’s time to go.”
“It’s only 11 o'clock.”
“It’s over there.”
It’s = It has (not possessive)
“It’s been a long time.”
“It’s been brewing awhile.”
“It’s got to happen soon.”
A Mnemonic Device:
It’s an apostrophe.
Or, put a more technical way, its is the possessive form of the neuter pronoun “it” — his, her, its.
Examples:
Its possessive
“Every dog has its day.”
“The jury has reached its decision.”
“Stop its momentum!”
“Guess its color.”
A Good Rule of Thumb:
If you can replace it with his or her, there's no apostrophe.
A Mnemonic Device:
The possessive dog had its tail removed.
Its’ is never correct. Ever.