Timer is a generative pre-trained transformer architecture designed as a foundation model for large-scale time series analysis. Built upon a decoder-only neural network structure similar to autoregressive language models, it processes temporal data by converting diverse time series into standardized single-sequence formats and learning temporal patterns through next-token prediction. This generative paradigm enables the model to address various downstream analytical tasks, including forecasting, missing data imputation, and anomaly detection, while demonstrating strong zero-shot and few-shot generalization across diverse domains.