Deadlines don’t care.
The Almanac does.

Dave: The final estimated payment for last year — freelancers and business owners, this one sneaks up right after the holidays.

Dave: Online returns and the balancing payment are both due — plus the first payment on account for the current year.

Dave: Employers and payers owe you these by month-end — missing one is a reason to call, not to wait.

Jaya: Missed your Initial Enrollment Period? This is the annual catch-up window — coverage starts the month after you sign up.

Jaya: The healthcare.gov window — enroll by December 15 for January 1 coverage in most states.

⚠ State-run exchanges set their own windows — a few differ from the federal dates.

Dave: Form 1120-S and 1065 — a month before personal returns, and the late-filing penalty is per-partner, per-month.

Jaya: Missed your Initial Enrollment Period? This is the annual catch-up window — coverage starts the month after you sign up.

Dave: Form 1040, the payment even if you extend, and Q1 estimated taxes — all on the same day.

Walter: The rare deadline that works in your favor — you can still fund last year's IRA or HSA right up to Tax Day.

Dave: New allowances, new thresholds — UK figures reset on the 6th, not January 1st.

Dave: Only two months after Q1 — the quarter everyone forgets because it isn't really a quarter.

Dave: US citizens abroad get two extra months automatically — but interest on any balance has been running since April.

Dave: The mid-year Self Assessment installment — six months after the January payment.

Dave: Also the extended deadline for S-corp and partnership returns — a heavy day for business owners.

Dave: The extension you filed in April runs out — and there's no extension on the extension.

Jaya: The annual window to switch between Original Medicare, Advantage, and Part D plans — changes take effect January 1.

Walter: Aid is first-come in many states, so early filing matters — the official target is October 1.

⚠ Recent cycles have opened later than October 1 — confirm the current year's date at studentaid.gov.

Dave: Filing on paper? Your deadline is three months earlier than online filers'.

Jaya: The healthcare.gov window — enroll by December 15 for January 1 coverage in most states.

⚠ State-run exchanges set their own windows — a few differ from the federal dates.

Norm: Most employer plans run their window in late fall — the one chance a year to fix coverage without a qualifying event.

⚠ Set by each employer — many run October–November, but yours may differ.

Walter: Required minimum distributions must be out by year-end — your very first one gets until April 1, but doubling up has tax consequences.

Dave: The plan must exist by December 31 to receive employee deferrals for the year — a SEP-IRA can wait until filing, a solo 401(k) can't.

Norm: Most FSA balances and many insurance benefits reset — check your plan's grace period or carryover before the year closes.

⚠ Some plans offer a grace period into March or a limited carryover — your plan documents control.

Jaya: The annual window to switch between Original Medicare, Advantage, and Part D plans — changes take effect January 1.