API Rest, what lastUpdateMicros is?

Hi,

what is parameter "lastUpdateMicros" and can I get real daytime from that?

I need to know since when some ASM objects are in staging and although I can see real daytime in GUI, in API I see only lastUpdateMicros like here:

{   u'allowed': True,
        u'checkPostDataLength': True,
        u'checkQueryStringLength': True,
        u'checkRequestLength': True,
        u'checkUrlLength': True,
        u'id': u'w2u9JYt-5pTrmHIhsrGXsA',
        u'kind': u'tm:asm:policies:filetypes:filetypestate',
        u'lastUpdateMicros': 1519382317000000.0,
        u'name': u'jpg',
        u'performStaging': True,
        u'postDataLength': 1000,
        u'queryStringLength': 1000,
        u'requestLength': 5000,
        u'responseCheck': False,
        u'selfLink': u'https://localhost/mgmt/tm/asm/policies/9gV6OhNsX7jnw9sPSfRGmQ/filetypes/w2u9JYt-5pTrmHIhsrGXsA?ver=12.1.2',
        u'type': u'explicit',
        u'urlLength': 100}

Thanks, Zdenek