The instrument currency regulation at 14 CFR 61.57(c)(1) contains a deliberate and consequential distinction in its language: it does not say "within the 6 months preceding the flight" or "within the preceding 180 days." It says "within the 6 calendar months preceding the **month** of the flight." That single word — month — transforms the calculation from a rolling day-count into a whole-calendar-month lookup. For a flight planned on July 16th, the relevant question is not whether the HITS were performed within 180 days of July 16th, but whether they were performed within any of the six calendar months that precede July. Those months are January, February, March, April, May, and June. January 3rd falls squarely within January. The pilot in the hypothetical is, by a straightforward textual reading of the regulation, current.
This interpretation is consistent with how the FAA has historically applied "calendar month" language throughout Part 61. The flight review provision at 61.56 uses the same construct — 24 calendar months — and it is well established that a flight review completed on January 1st remains valid through the last day of January two years later, not merely 730 days from the date of completion. Medical certificates follow identical logic. The FAA's choice of "calendar months" rather than a day-specific window is not accidental; it is a deliberate drafting decision that grants pilots the full extent of whatever calendar month they complete the action. Instrument currency is no different. A pilot who completes six approaches, holding, and tracking on January 3rd has satisfied the requirement for the entire month of January, and that month counts as one of the six preceding months for any flight taken in July.
The practical implication for working IFR pilots is meaningful. Under a naive 180-day reading, January 3rd would fall outside currency for a July 16th flight by roughly 13 days. Under the correct calendar-month reading, the pilot retains full currency through July 31st — nearly two additional weeks of legal IFR flight compared to a day-count approach. This gap widens further the earlier in a calendar month the HITS are performed. A pilot who completed approaches on January 1st and another who completed them on January 31st are identically situated with respect to July currency, even though their underlying recency differs by a full month. This is a feature of the regulatory structure, not a loophole.
Operators and chief pilots administering Part 91K and Part 135 programs should ensure their currency tracking systems account for calendar-month logic rather than defaulting to 180-day rolling windows, which some flight department software tools apply as a conservative approximation. A system that flags a January 3rd currency date as expired for a July 16th flight is technically incorrect and may generate unnecessary sim events or restrict pilots who are lawfully current. At the same time, pilots relying on early-month HITS completions to maximize their currency window should understand the outer limit: that same January 3rd currency expires at the end of July, and any IFR flight on August 1st or later would be illegal without additional logging. The calendar-month structure grants a wide window on the back end but closes sharply at midnight on the last day of the sixth succeeding month.