This week with Vulkan 1.3.273 are two new extensions: VK_KHR_calibrated_timestamps and VK_KHR_vertex_attribute_divisor.
VK_KHR_calibrated_timestamps is a promotion of the existing VK_EXT_calibrated_timestamps extension to now being under the formal Khronos "KHR" umbrella. VK_KHR_calibrated_timestamps from AMD / Intel / RasterGrid / Valve is an interface to query calibrated timestamps obtained quasi-simultaneously from two time domains. This can be important for VR/AR and other purposes for ensuring calibrated/synced presentation.
The other new extension is VK_KHR_vertex_attribute_divisor that is based on the existing VK_EXT_vertex_attribute_divisor. The VK_KHR_vertex_attribute_divisor extension adds a new property to indicate support for non-zero values. This allows the extension to be supported on implementations that traditionally only supported OpenGL ES.
More details on all of the Vulkan 1.3.273 changes via Vulkan-Docs on GitHub .