| # Time units | |
| ## Userspace exposed time units | |
| *zx\_time\_t* is in nanoseconds. | |
| Use [`zx_clock_get_monotonic()`] to get the current time as the number of nanoseconds since boot. | |
| ## Kernel-internal time units | |
| *lk\_time\_t* is in nanoseconds. | |
| When writing code that will run in the kernel, to read the current monotonic clock value, use: | |
| ``` | |
| #include <platform.h> | |
| lk_time_t current_time(void); | |
| ``` | |
| [`zx_clock_get_monotonic()`]: /reference/syscalls/clock_get_monotonic.md |