Authentication system for authenticating a person in different time intervals of a predetermined time interval group (A, B, C), wherein each predetermined time interval is assigned a different authentication scheme, comprising: a detection device, which is configured to detect at least one personal feature of a person in a current time interval of the time interval group (A, B, C); and a processor, which is configured to authenticate the person based on the authentication scheme associated with the current time interval, wherein the time interval group (A, B, C) comprises a first time interval and a second time interval, wherein the first time interval is assigned a first authentication scheme and the second time interval is assigned a second authentication scheme, wherein the first authentication scheme comprises the detection of the at least one personal feature, wherein the second authentication scheme comprises the additional detection of a second personal feature, wherein the detection device is configured to detect the at least one personal feature if the current time interval corresponds to the first time interval, and to additionally detect the second personal feature if the current time interval corresponds to the second time interval, wherein the processor is configured to authenticate the person based on the respective detected personal feature, wherein the detection device or the processor is configured to detect a time of the authentication of the person and to assign the detected time of the authentication to the first time interval or the second time interval, wherein at least one time interval of the predetermined time interval group (A, B, C) is characterized by a predetermined frequency of authentications, and wherein the processor is configured to monitor a frequency of authentications during operation in order to detect the reaching of the predetermined frequency, and wherein the processor is configured to adapt a start time and/or an end time of the at least one time interval of the predetermined time interval group (A, B, C) during operation, when the monitored frequency of authentications within the time interval falls below a predetermined first limit value or exceeds a predetermined second limit value outside the time interval. a detection device, which is configured to detect at least one personal feature of a person in a current time interval of the time interval group (A, B, C); and a processor, which is configured to authenticate the person based on the authentication scheme associated with the current time interval, wherein the time interval group (A, B, C) comprises a first time interval and a second time interval, wherein the first time interval is assigned a first authentication scheme and the second time interval is assigned a second authentication scheme, wherein the first authentication scheme comprises the detection of the at least one personal feature, wherein the second authentication scheme comprises the additional detection of a second personal feature, wherein the detection device is configured to detect the at least one personal feature if the current time interval corresponds to the first time interval, and to additionally detect the second personal feature if the current time interval corresponds to the second time interval, wherein the processor is configured to authenticate the person based on the respective detected personal feature, wherein the detection device or the processor is configured to detect a time of the authentication of the person and to assign the detected time of the authentication to the first time interval or the second time interval, wherein at least one time interval of the predetermined time interval group (A, B, C) is characterized by a predetermined frequency of authentications, and wherein the processor is configured to monitor a frequency of authentications during operation in order to detect the reaching of the predetermined frequency, and wherein the processor is configured to adapt a start time and/or an end time of the at least one time interval of the predetermined time interval group (A, B, C) during operation, when the monitored frequency of authentications within the time interval falls below a predetermined first limit value or exceeds a predetermined second limit value outside the time interval.