Simnet current time is always ahead

Smart Contracts
1

Trying out the new stacks-block-time in Clarity 4.

$ clarinet --version
clarinet 3.10.0
$ clarinet new asdf && cd asdf
$ clarinet contract new asdf

;; asdf.clar
(define-read-only (get-time) stacks-block-time)

// asdf.test.ts

import { describe, expect, it } from "vitest";

const accounts = simnet.getAccounts();
const address1 = accounts.get("wallet_1")!;

describe("get-time", () => {
  it("gets the current time", () => {
    simnet.mineEmptyBlock();
    const { result } = simnet.callReadOnlyFn("asdf", "get-time", [], address1);
    const expected = Math.floor(Date.now() / 1000);
    const actual = Number((result as any).value);
    expect(Math.abs(expected - actual)).toBeLessThan(10);
  });
});

$ npm install
$ npm test

 FAIL  tests/asdf.test.ts > get-time > gets the current time
AssertionError: expected 1809 to be less than 15
 ❯ tests/asdf.test.ts:13:41
     11|     const expected = Math.floor(Date.now() / 1000);
     12|     const actual = Number((result as any).value);
     13|     expect(Math.abs(expected - actual)).toBeLessThan(15);
       |                                         ^
     14|   });
     15| });

I also tried making sure the time was captured in the contract:

;; asdf.clar
(define-data-var t uint u0)
(define-read-only (asdf-get) (var-get t))
(define-public (asdf-set) (begin (var-set t stacks-block-time) (ok true)))

// asdf.test.ts
import { Cl } from "@stacks/transactions";
import { describe, expect, it } from "vitest";

const accounts = simnet.getAccounts();
const address1 = accounts.get("wallet_1")!;

describe("asdf", () => {
  it("gets what it sets", () => {
    simnet.mineEmptyBlock();
    expect(simnet.callPublicFn("asdf", "asdf-set", [], address1).result).toBeOk(Cl.bool(true));
    const { result } = simnet.callReadOnlyFn("asdf", "asdf-get", [], address1);
    const expected = Math.floor(Date.now() / 1000);
    const actual = Number((result as any).value);
    expect(Math.abs(expected - actual)).toBeLessThan(15);
  });
});

And observed a similar result. Taking a closer look, the simnet time is consistently around 1819s to 1820s ahead for this case. (1800s is 30 minutes.) I assume it has to do with moving the clock forward while network setup and contract deployment occurs. Removing the mineEmptyBlock drops this diff by 600s (10m).