"I am looking at some short term CDs through my brokerage account to park some of the fixed income allocation. I have waited a few weeks to see how the offerings change, and I am now wondering whether new CDs tend to be offered by banks more in the beginning, middle, or end of the month or if it is just random?"I have no idea how different brokerages add CD offerings to their lists.Banks and Credit Unions don't "offer" "new" CDs, like new bond issues. You can always get a CD at whatever maturities are available at a given bank or CU.Banks and Credit Unions do change the rates they pay on CDs on a regular basis. At my credit union, for example, posted rates are only good for a week, though in fact, rates change infrequently, and usually by no more than .1% or .15% APY.When contemplating getting a new CD, I usually wait until Friday to see if there has been any major change in 5-year and 10-year T-bills that week, since that is usually what precipitates a change in CD rates (they don't always act, but I don't think I've ever seen them change CD rates without some meaningful change in the bond market). If bonds are trending down, I'll jump on Friday; if up, I'll wait until the next week to see how things are going; if no change, I'll go to the bank on a day I'm walking by, anyway.