Last month, before Microsoft announced the Anniversary Update for Windows 10 (codename Redstone), we revealed that this big update would be made available in July.
Spotted in a recent document regarding the Universal Windows Platform and Xbox, Microsoft references Windows 10 "Version 1607," which follows the same versioning scheme as the last two Windows 10 releases, version 1511 and version 1507. This versioning means Microsoft is planning to launch Redstone 1 (Anniversary Update) in July rather than June, which would have been version 1606 instead.
If you take a look at the Windows 10 features roadmap site, Microsoft mentions "July 2016" when referring to new features arriving to Cortana:
Cortana is also the best digital assistant at reminders, letting you set them in more ways including by pen, and [coming in July 2016] pulling reminder-relevant info from emails so you have the details at hand. And you can instantly capture your ideas by voice just by telling Cortana to take a note
It is often that release dates slip and slide up until the very last minute, so it isn’t all that surprising to see the update launching a month later than scheduled. Originally it was supposed to be June, now it appears to be July. Either way, it will be worth the wait, considering Windows 10 Anniversary Update brings several cool new features to the operating system.
Thanks to @h0x0d for spotting the roadmap.