There have no limit on how many friends you can add in a day. But you could be band if fb team catch you to sending mass friend request. So keep adding friends in your own risk.
You can send three or four thousand friend requests in a single attempt using a contact file but there is some risk of getting banned if most of your requests are ignored.
There is no limit to how many friend requests you can send, but if they assume that you're spamming friend request then they will try and suspend you or worse, ban you.
I have always stuck with 20-25 people a day spreading them out at different times of the day and I have never had my account banned for adding to many people.
But by my idea..you can add as many as you want.. And for this you just need Emails of the friends you want to add and a phone verified account...
wow i see ! many people already added hundred friends in a day. then i am not getting access to that? fb blocked my friend request for two days for sending more than 20 friend request few days ago. they i am the victim?
I think in a day you can add at most 10 friends or so. Anything above it Facebook will show you a caution about adding too much friend in a day.