#ifndef _NTEXAPI_H
#if (PHNT_MODE != PHNT_MODE_KERNEL)
#if (PHNT_VERSION >= PHNT_WINDOWS_10)

/**
 * The NtCreateTimer2 routine creates a timer object.
 *
 * \param TimerHandle A pointer to a variable that receives the handle to the timer object.
 * \param TimerId For IR timers: A pointer to ULONG TIMERID (non-NULL). For non-IR timers: must be NULL.
 * \param ObjectAttributes A pointer to an OBJECT_ATTRIBUTES structure that specifies the object attributes.
 * \param Attributes Timer attributes (TIMER_TYPE).
 * \param DesiredAccess The access mask that specifies the requested access to the timer object.
 * \return NTSTATUS Successful or errant status.
 * \sa https://learn.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-createwaitabletimerexw
 */
_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
NtCreateTimer2(
    _Out_ PHANDLE TimerHandle,
    _In_opt_ PULONG TimerId,
    _In_opt_ PCOBJECT_ATTRIBUTES ObjectAttributes,
    _In_ ULONG Attributes,
    _In_ ACCESS_MASK DesiredAccess
    );

#endif
#endif
#endif
View code on GitHub

#ifndef _NTZWAPI_H

_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
ZwCreateTimer2(
    _Out_ PHANDLE TimerHandle,
    _In_opt_ PULONG TimerId,
    _In_opt_ PCOBJECT_ATTRIBUTES ObjectAttributes,
    _In_ ULONG Attributes,
    _In_ ACCESS_MASK DesiredAccess
    );

#endif
View code on GitHub