What days of the week does the irs disburse tax refund checks?

IRS Tax Refund Query by : What days of the week does the irs disburse tax refund checks? What days of the week does the irs disburse tax refund checks? I believed it was each friday but was informed it was a new technique so now am baffled so if i have dd date of the 25th but my bank it will be on the 25th or did they get sent a couple days ahead of and told to hold till the dd date