The speed at which alterations are completed can vary depending on several factors, including the complexity of the alteration, the availability of the tailor or seamstress, and the workload of the alteration service. In general, simple alterations can be completed within a few days, while more complex alterations may take longer. Here are some typical turnaround times for common alterations:

1. Hemming pants or skirts: Basic hemming can usually be done within a day or two, especially if the 24 Hours Alterations Services service offers same-day or express services.

2. Taking in or letting out garments: Alterations that involve taking in or letting out the waist, bust, or sleeves of a garment may take a few days to a week, depending on the workload and complexity.

3. Shortening sleeves or straps: Shortening sleeves or straps on garments like dresses or jackets usually takes a few days, as it involves careful measuring and stitching.

4. Replacing zippers or buttons: Repairing or replacing zippers or buttons can typically be done within a day or two, as long as the necessary materials are available.

5. Complex alterations or custom tailoring: Alterations that require significant modifications, such as reshaping a garment or creating a custom fit, may take a week or more. These alterations require more time and attention to detail.

It's important to note that these are general timeframes, and it's best to inquire directly with the alteration service to get a more accurate estimate. Some places offer rush or expedited services for an additional fee if you need the alterations done more urgently.