golang time.AddDate operation incorrect

[yanmxa]

Go version

go version go1.21.6 darwin/arm64

Output of go env in your module/workspace:

go env                              
GO111MODULE='on'
GOARCH='arm64'
GOBIN='/usr/local/go/bin'
GOCACHE='/Users/yanmeng/Library/Caches/go-build'
GOENV='/Users/yanmeng/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/yanmeng/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/yanmeng/go'
GOPRIVATE=''
GOPROXY='https://goproxy.cn'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.21.6'
GCCGO='gccgo'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/Users/yanmeng/Workspace/redhat/hub-of-hubs/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/4t/fhhxz9q56vd0mk9t7ytjpvbm0000gn/T/go-build2116447077=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

I want to obtain the current time for the previous month and the month before the previous month. I ran the following code:

package main

import (
	"fmt"
	"time"
)

func main() {
	current := time.Now()
	date1 := current.AddDate(0, -1, 0)
	date2 := current.AddDate(0, -2, 0)

	fmt.Println("date", current)
	fmt.Println("date1", date1)
	fmt.Println("date2", date2)
}

What did you see happen?

It echoes the following result

 $ go run time/main.go                                                                                                                                       [16:05:27]
date 2024-01-31 16:05:38.159025 +0800 CST m=+0.000179293
date1 2023-12-31 16:05:38.159025 +0800 CST
date2 2023-12-01 16:05:38.159025 +0800 CST

What did you expect to see?

 $ go run time/main.go                                                                                                                                       [16:05:27]
date 2024-01-31 16:05:38.159025 +0800 CST m=+0.000179293
date1 2023-12-31 16:05:38.159025 +0800 CST
date2 2023-11-31 16:05:38.159025 +0800 CST

[yanmxa]

Close it cause there is no 31th for some months

[yanmxa]

Ref:#31145