PHPRedis - time() does not work

I have a problem.

In my project I have few servers which modify same data in redis. All the servers may have different time. In other words, I can't rely on app server time in some cases.

So I would like to use Redis time as general base point.

Everything could be fine, PHPRedis documentation says there is a function which does exactly what I need: time().

But here is a BIG surprise:

//... create connection etc...
var_dump($redis->time());

Output is:

bool(false)

The question is - what the hell is this? Have you ever faced such a problem?

How can I get redis server time using it's functions?

Note: other redis functions work fine, I am able to read and write data. Connection is ok and is created correctly.

Solution

Got no help here.

As well as anywhere else.

So I needed to invent a walkaround...

Here is it, if someone needs it.

    // Generate unique temporary key
    $key = uniqid() . time();

    // Take some random future TS
    $future_ts = time() + 1000;

    $redis->setex($key, time(), 5);
    $redis->expireAt($key, $future_ts);

    // This variable now contains what I need
    $redis_ts = $future_ts - $redis->ttl($key);