The Notice of Appeal Is Deemed Filed When the Clerk Receives It...
... not when the clerk happens to get around to filing it.
In recent months – even before Covid, but even more since – I have seen clerks failing to promptly process filings. You have probably noticed it, too. Depending on the filing, this may create problems. For a notice of appeal, which has jurisdictional consequences, the date of filing is a matter of life or death to an appeal.
So what happens if you submit the notice of appeal timely, but the clerk does not actually "file" it until it is untimely?
J.M v. Los Angeles County Dept. of Children and Family Services (D2d2 Apr. 12, 2021) no. B305486 (not published) held: The appeal is timely. Fortunately, neither appelants' right to appeal nor the Court of Appeal's jurisdiction are at the mercy of a clerk's filing idiosyncrasies.