# TimeProviderNames Fields

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/)

## ActivationManagement {#activationmanagement-9508652d}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/activationmanagement-9508652d/)

```csharp
public const string ActivationManagement
```

The clock used by activation lifecycle management, including activation collection, migratability checks, repartitioning, and rebalancing.

## GrainDirectory {#graindirectory-2b4920fc}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/graindirectory-2b4920fc/)

```csharp
public const string GrainDirectory
```

The clock used by the grain directory cache for entry expiration.

## Grains {#grains-5a2c9b36}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/grains-5a2c9b36/)

```csharp
public const string Grains
```

The clock exposed to grains via `IGrainRuntime.TimeProvider` and used to drive grain timers.

## Membership {#membership-2dad5ce2}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/membership-2dad5ce2/)

```csharp
public const string Membership
```

The clock used by cluster membership loops, including the membership agent, membership table maintenance and cleanup, and silo health monitoring and probing.

## Messaging {#messaging-608ae956}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/messaging-608ae956/)

```csharp
public const string Messaging
```

The clock used by messaging infrastructure, such as request timeout tracking and gateway maintenance.

## SystemTimers {#systemtimers-fc6996a5}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/fields/systemtimers-fc6996a5/)

```csharp
public const string SystemTimers
```

The clock used by silo background maintenance loops driven by `IAsyncTimerFactory` (grain directory maintenance and similar), excluding cluster membership, which uses [TimeProviderNames](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.runtime.timeprovidernames/).