How to convert “yyyy-MM-dd'T'HH:mm:ssZZZZZ” to “yyyy-MM-dd” without add one day in Android?

问题

I am develop in Android

The day of String is 2020-04-23T23:59:59-04:00

And try to use the following function to convert the time to 2020-04-23

fun changeDateFormat(strDate:String):String {
    return SimpleDateFormat("yyyy-MM-dd").format(SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ").parse(strDate))
}

But it show 2020-04-24

Did I missing something ? Thanks in advance.

回答1:

here is how you can achieve it

val dateInString = "2020-04-23T23:59:59-0400"
val ldt: LocalDateTime = LocalDateTime.parse(dateInString, DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssZ"))
val currentZoneId: ZoneId = ZoneId.systemDefault()
val currentZonedDateTime: ZonedDateTime = ldt.atZone(currentZoneId)
val format: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd")
val formattedDate = format.format(currentZonedDateTime)
println(formattedDate)

回答2:

You should use DateTimeFormatter and LocalDate from java.time.

for example

val timestampAsDateString = "2020-04-23T23:59:59-04:00"
val format = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssZZZZZ")

val date = LocalDate.parse(timestampAsDateString, format)

Log.d("parseTesting","Date : ${date}") // logs 2020-04-23

since LocalDate is a date without time-zone in the ISO-8601 calendar system the output is already in yyyy-MM-dd format.

回答3:

Your time must not contain colon in between(-04:00)

This worked out well for me and returned the desired result

fun changeDateFormat(strDate:String):String {
    val sourceSdf = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.getDefault())
    val requiredSdf = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
    return requiredSdf.format(sourceSdf.parse(strDate))
}

来源：https://stackoverflow.com/questions/61379415/how-to-convert-yyyy-mm-ddthhmmsszzzzz-to-yyyy-mm-dd-without-add-one-day

标签

android

date

kotlin