
select toDateTime64(-86400 ,9,'UTC') ==  1969-12-31 00:00:00.000000000

select toDateTime64(-86400.00 ,9,'UTC') ==  1970-01-01 00:00:00.000000000 


However, I expect both outputs to be same. 

Version affected : 22.8
#include <DataTypes/DataTypeInterval.h>
#include <DataTypes/DataTypeAggregateFunction.h>
#include <DataTypes/DataTypeObject.h>
#include <DataTypes/ObjectUtils.h>
#include <DataTypes/DataTypeNested.h>
#include <DataTypes/Serializations/SerializationDecimal.h>
#include <Formats/FormatSettings.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnFixedString.h>
#include <Columns/ColumnConst.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnTuple.h>
#include <Columns/ColumnMap.h>
#include <Columns/ColumnObject.h>
#include <Columns/ColumnsCommon.h>
#include <Columns/ColumnStringHelpers.h>
#include <Common/assert_cast.h>
#include <Common/quoteString.h>
#include <Core/AccurateComparison.h>
#include <Functions/IFunctionAdaptors.h>
#include <Functions/FunctionsMiscellaneous.h>
#include <Functions/FunctionHelpers.h>
#include <Functions/DateTimeTransforms.h>
#include <Functions/toFixedString.h>
#include <Functions/TransformDateTime64.h>
#include <Functions/FunctionsCodingIP.h>
#include <DataTypes/DataTypeLowCardinality.h>
#include <Columns/ColumnLowCardinality.h>
#include <Interpreters/Context.h>