not one's day, this is

Idioms

Also, just one of those days. Nothing is going right for one today. For example, The car wouldn't start, it rained unexpectedly—this is not my day, or The phone has rung nonstop all morning; it's just one of those days. [c. 1920]

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023