| 摘要 |
A global time calculator includes an insert and a sleeve. The insert is marked on both its sides (or on a single page slide insert on one side) with vertical columns of incremental time designations, and may or may not contain a stop mechanism. The insert is slidable and connected with the sleeve so as to be shiftable in a vertical direction. Both sides of the sleeve (or in some embodiments a single side of the sleeve) have areas for obscuring vertically aligned time designations that are in excess of unobscured time designations.
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