The inflation-fueled frenzy to buy I Bonds led to an unprecedented volume of purchases in the last 24 hours, according to the U.S. Treasury Department.

As of 4 p.m. Friday, TreasuryDirect saw 68,751 online accounts created and $710 million in purchase requests for I Bonds in just one day. It’s an enormous amount when you consider that nearly $704 million in I Bonds was sold in the first two weeks of October, through Oct. 14, based on Treasury data.

Buyers wanted to lock in an annualized 9.62% rate for a six-month window. The rate looks great when many one-year certificates of deposit are paying 1% or less.

While many people got through successfully to buy I Bonds on Friday, others expressed a great deal of frustration, noting that when they tried to go to TreasuryDirect.gov, the site wasn't coming up on their computer screen. Or some said they were cut offline during the process. Some complained that they got locked out — and couldn't get back in Friday — when they didn't remember their security questions for Treasury accounts they had opened years ago.

If anyone had hoped to sit down Saturday morning and buy I Bonds, they're out of luck.

The TreasuryDirect site will go down for a scheduled maintenance beginning midnight Saturday through 11:59 p.m. Sunday, according to a post on TreasuryDirect late Friday afternoon.

Savers are told once again, though, that purchases that are completed before the scheduled maintenance will receive the much talked about annualized rate of 9.62% that will apply to the first six months after the bond's purchase. Another rate — likely to be about an annualized 6.48% — will apply to the following six months. That new rate will be announced Nov. 1.

More: Inflation drives ratesI Bonds can bring big deals for savers: Why you should buy before Oct. 28

The Treasury Department had told savers a few weeks ago that Oct. 28 was the final date to buy I Bonds to lock in that high attractive rate of 9.62% for the first six months after the bond is issued.

Most people wanted to buy in October so they can end up with an interest rate of about 8% over 12 months, after combining the 9.62% rate for the first six months and what's expected to be the new 6.48% annualized rate for the next six months.

Savers have been buying I Bonds — which can be bought for as little as $25 and up to $10,000 — for months ever since the exceptionally high rate was announced in May.

But last-minute glitches hit the system and frustrated some savers. Some who bought bonds Friday were fearful when they saw the bonds would have an issue date of Oct. 31. Did that mean they didn't make the cut? No, not at all.

More: High rate frenzyYou might not be able to get last-minute deal on I Bonds after Treasury website slowdowns

The TreasuryDirect site noted Friday: "This maintenance period will also ensure we are able to successfully process the unprecedented volume of I Bond purchases made in the past 24 hours. During this time the account management system will be unavailable."

The TreasuryDirect system will be open on Monday, allowing savers to create new accounts and buy bonds. But bonds bought on Oct. 31 will not receive that higher rate of 9.62% — the purchase had to go through by Oct. 28.

"Beginning Monday, purchases will receive the rate that will be published on Tuesday, Nov. 1," the site noted. "This new rate will be applied for six months after purchase."

Contact Susan Tompor: stompor@freepress.com. Follow her on Twitter @tompor. To subscribe, please go to freep.com/specialoffer. Read more on business and sign up for our business newsletter.

This article originally appeared on Detroit Free Press: I Bonds: $710M sold on TreasuryDirect in day as rate deadline nears