There's a lot of different ways to handle this but It's fairly simple to manipulate dates in vue if you pull in moment.js

https://momentjs.com/

Once setup you can do this in your vue component:

methods: {
    formatDate(date) {
        return moment(date).format('dd.mm.YYYY');
    },
}

You could also just format it in the php side as an accessor and send that along to your vue component and you wouldn't have to worry about formatting it in vue.

In some Model

...

protected $appends = ['some_date_formatted'];

public function getSomeDateFormattedAttribute()
{
    return Carbon::parse($this->some_date_field)->format('dd.mm.YYYY');
}

...

https://laravel.com/docs/5.7/eloquent-mutators#accessors-and-mutators

Many thanks for your reply.

I have problems in vue.

the form code has this row

<input type="text" class="form-control" v-model="newItem.tsmp" />

lumen delivers a timestamp. I have problems to convert the timestamp into german date.

This is not working:

<input type="text" class="form-control" v-model="newItem.tsmp | formatDate" />

Error: Property or method "formatDate" is not defined on the instance but referenced during render.

How can I solve this problem?

@MLUTZ - It'd be like this:

<input type="text" class="form-control" v-model="newItem.tsmp" :value="formatDate(newItem.tsmp)" />

I've got an error, too.

:value="formatDate(newItem.tsmp)" conflicts with v-model on the same element because the latter already expands to a value binding internally

i get the data from the lumen backend

...
    this.$http.get('http://api.test/termin/' + id)
         .then(function (resp) {
               app.newItem = resp.data;
         })
---

perhaps, i have an error in reasoning??

@MLUTZ - That's my fault, you'll have to handle it slightly different:

<input type="text" class="form-control" v-model="newItem.tsmp">

...
    this.$http.get('http://api.test/termin/' + id)
         .then(function (resp) {
        resp.data.tsmp = app.formatDate(resp.data.tsmp);
               app.newItem = resp.data;
         })
---

Yeah, you made my day. It works. Yesterday I tried a similar solution. But unfortunately with the wrong variables.

Great support @realrandyallen !

Thanks markus