| Error code | Description | Notes |
|---|
| JEWCAL_ERROR_OK | OK | |
| JEWCAL_ERROR_NULL_POINTER | NULL Pointer was passed | |
| JEWCAL_ERROR_INVALID_STRUCT_SIZE | Invalid structure size | |
| JEWCAL_ERROR_BUFFERTOOSMALL | Buffer too small | |
| JEWCAL_ERROR_INVALID_FLAGS | Invalid flags passed | |
| JEWCAL_ERROR_FILE_NOT_FOUND | File not found | since version 1.1, build 3 |
| JEWCAL_ERROR_INVALID_GREGORIAN_DAY | Invalid Gregorian day was passed | |
| JEWCAL_ERROR_INVALID_GREGORIAN_MONTH | Invalid Gregorian month was passed | |
| JEWCAL_ERROR_INVALID_GREGORIAN_YEAR | Invalid Gregorian year was passed | |
| JEWCAL_ERROR_INVALID_HEBREW_DAY | Invalid Hebrew day was passed | since Version 1.1 |
| JEWCAL_ERROR_INVALID_HEBREW_MONTH | Invalid Hebrew month was passed | |
| JEWCAL_ERROR_INVALID_HEBREW_YEAR | Invalid Hebrew year was passed | |
| JEWCAL_ERROR_NO_SHABBAT | Passed date is not a shabbat | |
| JEWCAL_ERROR_INVALID_DST | Invalid Daylight Savings Time structure | |
| JEWCAL_ERROR_NO_OMER_COUNT | No Omer count | since Version 1.1, build 2 |
| JEWCAL_ERROR_CITY_NOT_FOUND | City was not found | |
| JEWCAL_ERROR_INVALID_LATITUDE | Invalid latitude was passed | |
| JEWCAL_ERROR_INVALID_LONGITUDE | Invalid longitude was passed | |
| JEWCAL_ERROR_INVALID_TIMEZONE | Invalid timezone was passed | |
| JEWCAL_ERROR_CALCULATE_ZMANIM_FAILED | Calculation string is invalid | |
| JEWCAL_ERROR_PARASHGETREADINGS_FAILED | Internal function ParashGetReadings failed | |
| JEWCAL_ERROR_NO_ASTRONOMICAL_EVENT | Astronomical event does not occur | |