Fix timestamp codec len calculation (#1258) #7577

Job	Run time
Lints and doc tests on ubuntu-latest	8m 46s
Typos Check	4s
Lints and doc tests on windows-latest	11m 59s
Unit tests on ubuntu-latest	18m 46s
Lints and doc tests on macos-13	9m 41s
Unit tests on windows-latest	33m 6s
Lints and doc tests on macos-14	5m 5s
Unit tests on macos-13	13m 0s
Unit tests on macos-14	10m 23s
Memory leak checks	2m 32s
CI status checks	1s
	1h 53m 23s

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