I'm would like to get the number of value transactions (either tokens deposit or withdrawal) for a specific contract (I got its address) in the last 24 hours and also the total so far.
Is it possible? Say using etherscan.io or something similar?
You can use etherscan for this. you will get a list of "ERC20 - Token Transfer Events" by Address:
As you can specify the address, start, and end blocks as parameters you can make a simple calculation of the number of blocks expected in 24 hours.
Then you will retrieve the list of transactions during the last 24 hours.
Also notice that each transaction has a timestamp.
Hope this helps.