The tie is still set to take place on Sunday 23 April, but kick-off at the Academy Stadium has now been amended to 18:45 (UK).
It will also be broadcast live on Sky Sports in the United Kingdom.
City are currently unbeaten in our last 13 WSL matches, a run which stretches back to September.
The Hammers, meanwhile, currently sit seventh in the table and are without a league win since December.
Gareth Taylor's side earned a hard-fought 1-0 victory away to the Hammers in the reverse fixture.
Khadija 'Bunny' Shaw grabbed the only goal of the game on that occasion in our first match of 2023.
CITY V CHELSEA APP COVERAGE
As always, you can follow comprehensive coverage of our WSL clash with Chelsea on the official Man City app.
Our Matchday Centre, offering detailed text updates, stats and analysis across the day, begins at 11:00, while a special Matchday Live show will also be broadcast ahead of kick-off.
Once the action gets under way, we will provide live audio commentary in the app, while those with push notifications turned on will also be alerted to all the key moments as they unfold.
A detailed match report and reaction from the manager and players alike can be accessed soon after the final whistle, while highlights and a full-match replay (available on CITY+ and Recast) will be made available from 12:00 on Monday 27 March.