Apple delays its return to office as the Delta variant surges.

Apple pushed back its return-to-office plans by at least a month in response to the recent surge in coronavirus cases, which has been fueled by the spread of the Delta variant.

The company told employees on Monday that they are now expected to return to the office as early as Oct. 1 instead of early September. The company said that the date could shift further depending on the spread of the virus, and that it would give employees at least a month’s notice before they are expected to return, according to an email Apple sent to employees, which was viewed by The New York Times.

“As the situation continues to evolve, we’re committed to the same measured approach that we have taken all along,” the email said.

Some employees, such as those who build hardware, have already returned to Apple’s offices. At the beginning of the pandemic, Apple closed many of its retail stores, but those have since reopened. Apple’s return-to-work policies apply to all of its offices, including those in California, Texas and New York.

Apple declined to comment further. The company had 147,000 full-time employees as of September. Bloomberg earlier reported the changed return-to-office date.

Like many companies, Apple has delayed its employees’ return date several times, but it is one of the first major corporations to respond to the Delta variant spread.

Throughout the pandemic, Silicon Valley has been at the forefront of the trend toward remote work, with tech companies like Twitter and Facebook among the first to order their employees to work from home in early 2020. Many tech companies also eventually decided to make remote work permanent.

But Apple has been more resistant to lose its in-person office culture, which has caused some friction among employees who want to continue working from home. An internal Slack channel called “Remote Work Advocates” has grown to about 6,500 employees from roughly 1,800 in June, according to Cher Scarlett, an Apple security engineer who has helped write letters to management from the group.

In June, about 1,800 workers signed a letter to Tim Cook, Apple’s chief executive, that said forcing employees back into the office would cause some people to leave the company. On Monday, some employees in the Slack group posted a second letter to send to management that proposed more flexible remote-work arrangements. Tech news sites The Verge and Recode previously reported on the letters.

“Basically, everybody wanted to feel heard and to have more transparency and flexibility, like we’re seeing in other companies of Apple’s size,” Ms. Scarlett said.