A headline on Google News today, attributed to the BBC, reads,

Grenfell Tower fire:  Minute’s silence marks one-year anniversary

Apparently somebody got to the BBC, though, because the web site now shows this headline:

Grenfell Tower fire: Silent walk marks first anniversary

The word anniversary already includes the concept of a year.  It comes from Latin annus (= a year) and versus, past participle of verto (= to turn), and means [the day] of the turning of a year.  To add “year” to it is like saying “your birthday day”.

I keep reading, though, of “one-year” and “ten-year” anniversaries.  Maybe people have started adding “year” to anniversary because of the even stupider practice of celebrating “one-month” and “six-month” and suchlike “anniversaries”.