Yes, the first day is counted towards the ATM holds, regardless of whether calendar or business hold days are used. 

Below are some examples:

Business Day Holds

Deposit 1
3/28 Friday (hold day 1)   3/29 Saturday (doesn’t count)   03/30 Sunday (doesn’t count)   03/31 Monday (hold day 2)   04/01 - Release in AM
 
Deposit 2
3/29 - Saturday (hold day 1)   03/30 - Sunday (doesn’t count)   03/31 – Monday (hold day 2)   04/01 - Release in AM
 
Deposit 3
03/30 - Sunday (hold day 1)   03/31 - Monday (hold day 2)   04/01 - Release in AM

Deposit 4 (example of two day hold)

5/19 Monday (hold day 1)   5/20 Tuesday (hold day 2)   5/21 Wednesday (release in AM)  

Calendar Day Holds

Deposit 1
3/28 Friday (hold day 1)   3/29 Saturday (counts, hold day 2)    3/30 Sunday (counts, release in AM)  

Deposit 2
3/29 Saturday (counts, hold day 1)     3/30 Sunday (counts, hold day 2)     3/31 - Monday release in AM

Deposit 3
3/30 Sunday (counts, hold day 1)   3/31 Monday (hold day 2)   4/1 - release in AM