Finding time for the associate editor job – should one ask institute's management?

An early career researcher (ECR) is asked to become an associate editor for a reputable classical journal. Of course, no renumeration is offered. Based on the experience of other ECRs in a similar situation, I estimate that the job takes on average one full working day per month, or about 5% of working time. Let’s not discuss working doing this job in the evenings or weekends (as, most surely often happens in reality). Let’s say the ECR will take time from the regular working hours to do the editorial tasks. Now, the question: does the ECR have to discuss the decision of taking the associate editorship with the institute’s management? On the one hand, becoming an associate editor is considered cool for the ECR’s CV. So, it’s not directly evident why the institute should pay for the working hours. On the other hand, helping to carry on with the semi-broken peer-review system is considered a common duty for all the academics, including the academic institutions.