Assuming we classify your submission as research you can expect the following timeline:
1. From submission to editorial evaluation: About 2 weeks. It depends a little on day of submission, how many other articles arrive at the same time, how complex your submission is to triage, etc.
2. From editorial evaluation to peer-review: Zero days or more. This depends on the level of revisions we ask for during triage, and how quickly you can respond.
We have quite exacting open data policies and a detailed triage process - if you sail through with no requested revisions, then we will go to peer-review immediately.
If we request revisions, the time it takes will depend on how many revisions we request, how complex they are, and how much back-and forth is needed until both sides are happy with things and we can go into peer-review.
3. Receipt of first round of peer-review comments: About 4 weeks on average at the moment, but it varies. This depends heavily on the complexity of the manuscript, comments and how easy it is to find willing peer-reviewers (which can depend on time of year - summer and winter holidays are particularly challenging for finding reviewers, and so is the start of university terms).
We aim for 3 reviewers, sometimes 4 depending on submission type, so the probability of one reviewer being delayed in providing comments can be high.
We keep in regular contact with reviewers and encourage them to move forward on comments as best we can, but are working in the constraints of a voluntary system.
4. Receipt of first round of comments to final decision: This depends on the complexity of revisions and how many rounds of back-and-forth we need to resolve them.
We hope that via our consensus process we could deal with complex issues via asynchronous discussion with the reviewers (saving a round or two of revisions) but this stage is unpredictable in terms of time.
Some manuscripts will go through the system quite quickly (as few as 6 weeks, if there are few comments in triage or peer-review).
Manuscripts that have more issues will take longer - 1 round of triage revision plus two rounds of peer-review revision will take about 12-14 weeks, plus however long the authors spend revising their manuscript between rounds.