# Why isn't the timestamp updating in this Playground example

**URL:** <https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071>\
**Category:** Language Support\
**Tags:** Motoko\
**Created:** [November 8, 2024, 10:40pm UTC](https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071 "2024-11-08T22:40:04Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![icme](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/icme/32/4327_2.png) [@icme](https://forum.dfinity.org/u/icme)\
**Post date:** [November 8, 2024, 10:40pm UTC](https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071/1 "2024-11-08T22:40:04Z")

</div>

I’m testing out some code making calls between a calling canister and a receiving canister

Caller - [Motoko Playground - DFINITY](https://m7sm4-2iaaa-aaaab-qabra-cai.raw.ic0.app/?tag=3131205961)  
Receiver - [Motoko Playground - DFINITY](https://m7sm4-2iaaa-aaaab-qabra-cai.raw.ic0.app/?tag=949884630)

This is the canister API that I’m calling

```auto
public shared func callReceiver() : async TimeResult {
    let startTimestamp = abs(now());
    let receiverActor = getReceiverActor();
    let receivedExecutedTimestamp = await receiverActor.call();
    let endTimestamp = abs(now());

    {
      startTimestamp;
      receivedExecutedTimestamp;
      endTimestamp;
      timeToReceiverInMs = (receivedExecutedTimestamp - startTimestamp) / 1_000_000;
      roundTripTimeInMs = (endTimestamp - startTimestamp) / 1_000_000;
    }
  };

```

And this is the result I’m receiving

```auto
(record {
  timeToReceiverInMs=0;
  roundTripTimeInMs=0;
  endTimestamp=1731105528705974575;
  startTimestamp=1731105528705974575;
  receivedExecutedTimestamp=1731105528705974575
})

```

Why are all the timestamps the same? I would expect the receiving canister to execute with a different timestamp, and then the final end timestamp to execute later. Like this:

1. `t1` - Caller processes ingress message and records `startTimestamp` at time `t1`
2. `t1` - Caller initiates call to receiver at time `t1`
3. `t2` - Receiver processes inter-canister (same subnet) call from caller at time `t2` and returns `t2` as `receivedExecutedTimestamp` back to the caller
4. `t3` - Caller receives response back from receiver at time `t3` and records `endTimestamp`

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<div class="post-metadata">

**Author:** ![icme](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/icme/32/4327_2.png) [@icme](https://forum.dfinity.org/u/icme)\
**Post date:** [November 8, 2024, 11:16pm UTC](https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071/2 "2024-11-08T23:16:16Z")

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Looking into this further, the Motoko Playground is on this subnet [https://dashboard.internetcomputer.org/subnet/pae4o-o6dxf-xki7q-ezclx-znyd6-fnk6w-vkv5z-5lfwh-xym2i-otrrw-fqe](https://dashboard.internetcomputer.org/subnet/pae4o-o6dxf-xki7q-ezclx-znyd6-fnk6w-vkv5z-5lfwh-xym2i-otrrw-fqe), which has 2.8k canisters. It seems like pae4o-o6dxf-xki7q-ezclx-znyd6-fnk6w-vkv5z-5lfwh-xym2i-otrrw-fqe is a closed (not public) subnet.

Is it possible that there’s such low load on this subnet that all messages can be processed in a single round and the same subnet inter-canister is near 0?

So then with a bunch of spare compute capacity can same subnet inter-canister messages go through consensus and be executed in a single round with 0 latency? Also, for clarity these are update call and not composite queries.

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<div class="post-metadata">

**Author:** ![skilesare](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/skilesare/32/5609_2.png) [@skilesare](https://forum.dfinity.org/u/skilesare)\
**Post date:** [November 8, 2024, 11:45pm UTC](https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071/3 "2024-11-08T23:45:58Z")

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Every canister that execute during a single block shares the same blocked timestamp for Time.now. since those canisters are on the same subnet It’s possible for them to share at the same time . I’m guessing we’re just seeing this now because of the new scheduler code that allows many more canisters to have a chance to execute in a round Instead of round robining.

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<div class="post-metadata">

**Author:** ![emmawatson](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/emmawatson/32/21782_2.png) [@emmawatson](https://forum.dfinity.org/u/emmawatson)\
**Post date:** [November 9, 2024, 9:25am UTC](https://forum.dfinity.org/t/why-isnt-the-timestamp-updating-in-this-playground-example/37071/4 "2024-11-09T09:25:33Z")

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Yes, since all canisters on the same subnet share the same blocked timestamp, it’s likely why you’re seeing identical timestamps. The new scheduler allows more canisters to execute in a round, which could explain this behavior.