I see, in that case we will have to fall back on the underlying SDK method.
Try it like this (you need to be connected to the vCenter)
$si = Get-View ServiceInstance
$optMgr = Get-View $si.Content.Setting $spec = @() $event1 = New-Object VMware.Vim.OptionValue
$event1.key = "event.maxAge" $event1.value = 120
$spec += $event1
$event2 = New-Object VMware.Vim.OptionValue
$event2.key = "event.maxAgeEnabled" $event2.value = $true
$spec += $event2
$task1 = New-Object VMware.Vim.OptionValue
$task1.key = "task.maxAge" $task1.value = 120
$spec += $task1
$task2 = New-Object VMware.Vim.OptionValue
$task2.key = "task.maxAgeEnabled" $task2.value = $true
$spec += $task2
$optMgr.UpdateOptions($spec)