Storrito requires at least one minute between two Stories scheduled for the same account. If you try to save two rows on the same minute in Bulk Scheduling, the row shows an error and blocks saving until the times are spaced out.
Before this rule, several Stories set for the exact same minute ran into two problems: the order they actually posted in wasn't guaranteed, and posting several Stories at once could cause queue delays — in some cases a Story missed its window entirely because the queue outlasted the retry. Spacing posts at least a minute apart keeps the posting order predictable and avoids those delays.
In Bulk Scheduling, a row that shares its minute with another row shows an error with a Move to next free minute button that resolves it in one click. To shift several posts at once while keeping the gaps between them, use Shift by in the toolbar. See Bulk Scheduling for the full walkthrough.
The one-minute rule applies per account. Two different accounts can still post at the same minute — the limit is only on multiple Stories queued for the same account at once.