at my birthday / at my birthday party

[xiaoen]

I saw Jennifer at my birthday party.

Hi,
Is the above sentence OK if I omit "party" from the end?

I mean => I saw Jennifer at my birthday.

Does it work?

 

[emsr2d2]

If the listener was already aware that you had a party or similar event for your birthday, you could omit the word "party".

 

[xiaoen]

Thank you.
And can we use "in" instead of "at" with "birthday"?

I mean "I saw Jennifer in my birthday."

 

[xiaoen]

In Longman Dictionary I found an example in which "on" is used instead of "at":

On my birthday in November we again lobbied the guards to have the radio for the day.

What's the reason? Why not "at"? When should we use "on" and when "at" with "birthday"?

 

[Rover_KE]

I would never say 'at my birthday' – only 'on my birthday'. It's a day like any other, though others may disagree.

'Let's meet on Tuesday/on 5th December/on Christmas Day/on my birthday.'

'I'll see you at my birthday party' is just fine.

 

[xiaoen]

I saw Jennifer at my birthday.:cross:
I saw Jennifer on my birthday.:tick:

Am I right?