Wibu to leave work at this time?

[Thisisthebeginning]

Started a part time job last week, through an agency. Was down to work until X time but the manager came in around 45 minutes before this and said, ' there's never anything to do at this time and I know you've got a long commute so you can go whenever you're ready".
I really appreciated this and set off soon after.
This week, I was working with 2 others. Again, we finished well in advance, there was no other work scheduled for that time and I had already finished everything an hour ago.
The 3 of us were sitting for 30 mins just looking at our phones and sitting around. I noticed no signs of anyone getting ready to go. At the end of the 30 mins, same as last week, I got my coat and belongings ready, stood up and told them I was heading home.
They weren't making a move at all and were still sitting their on their phones. I felt like some sort of slacker but if we had been told we could go once the work was done then don't see the point of sitting there on our phones for the sake of it?
The 2 colleagues might gossip why I'm leaving earlier but let them I guess.

She said, "We never have any work at this time, so go whenever you're ready"
Which I took to mean that you're welcome to stay if you've stuff to do but you don't have to.

I don’t know if I’ve missed what you say you do for work but there are certainly jobs where cover is necessary from the point of view of being present as a point of contact for queries, both email and or phone, just in case even if it’s quiet. It can look really bad if there’s no one available in some business areas. Even if it’s an internal facing role there are KPIs. However it does sound as they don’t need all of you at the same time but they should sort a rota for the quieter times and reduce the day rate. You’ll be paid for a set number of hours and if you are clocking off early you’ll need to reflect that in your agency time sheet.

If that's all she said she definitely only meant that day

I will check next week though just in case!
Same with the mornings, if she's told me, 'just arrive anytime before X' time' then that's what I'll do as long as my work is done. What's the point in arriving 30 mins earlier just to sit on my phone some more? The colleagues can gossip if they like

How did you take that to mean she definitely only means one day if she's said 'never'? Don't understand!

Yes but don’t falsify your time sheet if you use them . Apologies if I’m getting the wrong end of the stick

We don't use them, I will stay next time just in case, and the time after.

I do wonder if the daily rate was based on x hours so you’ll be paid less. I guess you’ll find out on payday, unless you could check with the agency. That would be the only reason colleagues aren’t killing time on their phones.

Because if she meant ever she'd have told everyone and reduced your hours

The first time you weee directly told you could leave, the second time you weren’t. F the others have been there longer, take your lead from them.
There aren’t (presumably) rules for just one person.
I might let someone leave a touch early but if it was expected, that would make rritate. I’d make it clear it wasn’t to happen again.

Being new to the job, i wouldn't have done so.

OK my reading of it is...

It's never busy at this time = letting you know that after x time it is quieter/less to do, in case you were wondering about what you should be doing.

I manage a team at work, and on the first week I might offer people an early finish. It doesn't mean they can do that every day. As they settle, we'd expect them to look for more work to fill their time

so I'd not assume that the offer to head whenever you're ready was a daily thing.

Just ask, that will sort it out.

The start time is different as it sounds like she said you don't need to come in until X. Which is more definite than "head off whenever"

I appreciate it sounds like I am splitting hairs, but I think the morning is clear, evening isn't.

It might be a case of you're required to do a list of tasks and if you get through them more quickly than others, they are happy for you to go.

I'd probably have stayed if everyone else was, but as you had previously been told you could go early when there wasn't any work, I don't think it was unreasonable of you to think you could go earlier.

It's also possible that your colleagues were staying or arriving early because they needed to for their own reasons too - I always get to work early because I use public transport which is rubbish in my area, so I don't have a choice.

Definitely worth checking with your manager. I know pp are saying why are they hiring 3 people when there's not enough work, but a lot of places seem to do that. I've definitely worked with people who do very little in the entire day, and the managers don't really care.

I think you need written clarification from your manager that it's okay to arrive at Y and leave at X.

What your colleagues do shouldn't really matter - maybe they're waiting for the bus or have to pick their kids up from childcare so would rather wait inside in the warm!