Method for determining a spectrum of a sample comprising one or more constituent parts on the basis of a time the one or more constituent parts require to undergo a physical process or chemical process, wherein the spectrum is determined by: a) dividing the sample by a modulation unit (2, 102) into assays for which the physical process or chemical process is initiated successively, timed according to a modulation pattern which is a function composed of N consecutive modulation functions (23.1, 23.2, 23.3) with N being 2 or larger; b) measuring with a detector (4, 104) in N consecutive cycles (25.1, 25.2, 25.3) a time when the constituent parts of the sample have completed the physical process or chemical process, wherein in succession of the cycles (25.1, 25.2, 25.3), each cycle (25.1, 25.2, 25.3) is assigned to a consecutive one of the modulation functions (23.1, 23.2, 23.3) within the modulation pattern, wherein each cycle (25.1, 25.2, 25.3) is started with an offset (26.1, 26.2, 26.3) in time as compared to a start (22.1, 22.2, 22.3) of the modulation function (23.1, 23.2, 23.3) it is assigned to, wherein for each cycle (25.1, 25.2, 25.3), the offset (26.1, 26.2, 26.3) is different, wherein the detector (4, 104) provides a detector signal providing information on when what number of constituent parts have completed the physical process or chemical process and wherein the detector signal has a detection time resolution, wherein at least one of the offsets (26.1, 26.2, 26.3) has an absolute value different from zero, different from the detection time resolution and different from multiples of the detection time resolution; and c) calculating a correlation of the detector signal and the modulation pattern with a calculation unit (5, 105), wherein for calculating the correlation of the detector signal and the modulation pattern, each cycle (25.1, 25.2, 25.3) and the modulation function (23.1, 23.2, 23.3) the respective cycle (25.1, 25.2, 25.3) is assigned to are treated as an entity (21.1, 21.2, 21.3) having a local timeline, wherein for each entity (21.1, 21.2, 21.3), the modulation function (23.1, 23.2, 23.3) of the respective entity (21.1, 21.2, 21.3) starts on the local timeline of the respective entity (21.1, 21.2, 21.3) at a predetermined time which is for all entities (21.1, 21.2, 21.3) the same, wherein the detector signal of each cycle (25.1, 25.2, 25.3) is considered as a separate signal of the respective cycle (25.1, 25.2, 25.3) and thus of the entity (21.1, 21.2, 21.3) the respective cycle (25.1, 25.2, 25.3) belongs to, wherein each of the separate signals starts with the corresponding cycle (25.1, 25.2, 25.3), wherein the correlation of the detector signal and the modulation pattern is calculated with the calculation unit (5, 105) by first correlating for each entity (21.1, 21.2, 21.3) the separate signal of the respective entity (21.1, 21.2, 21.3) with the respective entity (21.1, 21.2, 21.3)'s modulation function (23.1, 23.2, 23.3) in order to obtain for each entity (21.1, 21.2, 21.3) an array of data points, by second providing each array of data points on the local timeline of the respective entity (21.1, 21.2, 21.3) and by third treating the local timelines of the entities (21.1, 21.2, 21.3) as being the same and combining the data points of the obtained arrays to one array of data points which is the correlation; or by first providing for each entity (21.1, 21.2, 21.3) the separate signal of the respective entity on the local timeline of the respective entity (21.1, 21.2, 21.3), by second treating the local timelines of the entities (21.1, 21.2, 21.3) as being the same and combining the separate signals of the entities (21.1, 21.2, 21.3) to one virtual signal and by third correlating the virtual signal with one of the modulation functions (23.1, 23.2, 23.3) within the modulation pattern, wherein the modulation functions (23.1, 23.2, 23.3) within the modulation pattern are the same. a) dividing the sample by a modulation unit (2, 102) into assays for which the physical process or chemical process is initiated successively, timed according to a modulation pattern which is a function composed of N consecutive modulation functions (23.1, 23.2, 23.3) with N being 2 or larger; b) measuring with a detector (4, 104) in N consecutive cycles (25.1, 25.2, 25.3) a time when the constituent parts of the sample have completed the physical process or chemical process, wherein in succession of the cycles (25.1, 25.2, 25.3), each cycle (25.1, 25.2, 25.3) is assigned to a consecutive one of the modulation functions (23.1, 23.2, 23.3) within the modulation pattern, wherein each cycle (25.1, 25.2, 25.3) is started with an offset (26.1, 26.2, 26.3) in time as compared to a start (22.1, 22.2, 22.3) of the modulation function (23.1, 23.2, 23.3) it is assigned to, wherein for each cycle (25.1, 25.2, 25.3), the offset (26.1, 26.2, 26.3) is different, wherein the detector (4, 104) provides a detector signal providing information on when what number of constituent parts have completed the physical process or chemical process and wherein the detector signal has a detection time resolution, wherein at least one of the offsets (26.1, 26.2, 26.3) has an absolute value different from zero, different from the detection time resolution and different from multiples of the detection time resolution; and c) calculating a correlation of the detector signal and the modulation pattern with a calculation unit (5, 105),