ORDER

Appellees have filed a motion seeking leave to file a late cost bill. Under the circumstances presented by the motion, we grant the motion.

[*1165] Under Fed. R.App. P. 39(d)(1), a party who seeks costs taxed against the opposing party must file an itemized and verified bill of costs with the Circuit Clerk of Court within fourteen (14) days from the date of entry of judgment. Pursuant to Ninth Cir. Rule 39-1.4, “[u]ntimely cost bills will be denied unless a motion showing good cause is filed with the bill.” We have strictly enforced this requirement, holding that neither a mistake in calendaring, nor negligence in office administration constitutes good cause. Mollura v. Miller, 621 F.2d 334, 336 (9th Cir.1980).

However, this case presents a situation under which the late filing was due to national circumstances beyond counsel’s control. Our opinion in this matter was filed by the Clerk on September 12, 2001. On September 11, 2001, the United States Secretary of Transportation and the Administrator of the Federal Aviation Administration temporarily closed United States airspace to commercial aviation. As a consequence, Appellees’ counsel did not receive the decision until September 26, 2001. Upon receiving the decision, counsel compiled the cost bill and mailed it, along with supporting motion and affidavit, on September 28, 2001. The cost bill was received by the Clerk of Court on October 2, 2001.

Because the late filing was occasioned by national mail delays beyond counsel’s control, we grant the motion to file a late cost bill. See Knoblauch v. Comm’r, 752 F.2d 125, 128 (5th Cir.1985) (holding that holiday-related mail delays justified a late filing of cost bills).

Accordingly, Appellees’ motion to file a late cost bill is GRANTED. The Clerk of Court is directed to file the cost bill received on October 2, 2001. Costs are taxed against the Appellant in the amount of one hundred fifty-five dollars and forty-seven cents ($155.47). The Clerk is directed to amend the mandate accordingly.